For background on the Solar Energy Technologies Office (SETO) photovoltaics projects and office-wide strategy, be sure to read the Solar Energy Technologies Office Multi-Year Program Plan and the Solar Futures Study. Learn more about projects in the areas below. In each research topic area, projects are organized alphabetically by awardee name.

 

Project Name: Diagnosing and Overcoming Recombination and Resistive Losses In Non-Silicon Solar Cells Using a Silicon-Inspired Characterization Platform
Awardee: Arizona State University
Location: Tempe, Arizona
DOE Award Amount: $1,140,000
Principal Investigator: Zachary Holman
Project Summary: The goal of this project is to develop a characterization platform for non-silicon-based devices in order to gather a precise accounting of power losses that limit device performance. While tools and techniques for silicon-based devices are available, there aren’t comparable ones for non-silicon devices. Novel amorphous silicon contacts applied to cadmium telluride absorbers will be characterized using multiple bulk and interface loss-analysis methods. Using this methodology, the team will examine a wider range of absorber materials and create a platform that enables users to rapidly and accurately assess the quality of a wide range of bulk materials and surface passivation layers, including contact selectivity and contact resistivity. 

Project Name: Post-growth Recrystallization by Halides for High Throughput CIGS Photovoltaics
Awardee: Colorado School of Mines
Location: Golden, Colorado
DOE Award Amount: $900,000
Principal Investigator: Angus Rockett
Project Summary: This project uses a combination of a highly adaptable multi-source deposition system and a wide range of post-deposition treatments in an effort to identify successful routes of improving the structural and electronic properties of copper indium gallium selenide films that are compatible with high-throughput manufacturing. If successful, new treatments that use alkali metals, halides, and other extrinsic dopants may be identified that could either improve the performance of copper indium gallium selenide produced using two step production methods and/or reduce the manufacturing costs of copper indium gallium selenide production using single step production methods.

Project Name: High-Speed, Roll-to-Roll Production of Durable, Low-Cost, Bifacial Perovskite Photovoltaic Modules
Awardee: Energy Materials Corp.
Location: Rochester, New York
DOE Award Amount: $4,000,000
Principal Investigator: Thomas Tombs
Project Summary: Energy Materials Corp. (EMC) is developing low-cost, high-efficiency, high-stability, bifacial, thin-film solar modules using roll-to-roll printers at the former Kodak manufacturing facility. EMC and partners will create new methods to deposit layers of material to make the cell, develop a high-speed process using intense pulsed light to fuse the layers, resolve causes of degradation, and produce prototypes. The high-speed manufacturing process could eventually result in gigawatt-scale production.

Project Name: Development of Organic-Inorganic Hybrid Selective Layers via Vapor Phase Infiltration to Enhance the Durability of Perovskite Solar Cells
Awardee: Georgia Institute of Technology
Location: Atlanta, Georgia
DOE Award Amount: $300,000
Principal Investigator: Juan-Pablo Correa-Baena
Project Summary: A primary mechanism for perovskite solar cell failure is crystallization of small molecule layers in the cell. This project improves perovskite solar cell stability by embedding metal oxide clusters within these small molecule layers using vapor phase infiltration (VPI). These embedded metal oxide clusters restrict motion of the molecules and impede crystallization. This unique hybrid small molecule-metal oxide cluster layer will increase stability of these perovskite solar cells, a key step towards their commercialization.

Project Name: Development of a Low-Cost Single Crystal Silicon Substrate Process for >23% Solar Cells
Awardee: Leading Edge Crystal Technologies
Location: Gloucester, Massachusetts
DOE Award Amount: $2,500,000
Principal Investigator: Nathan Stoddard
Project Summary: This project is improving Leading Edge’s floating-silicon method for producing high-quality single crystalline wafers, as opposed to the conventional process of using wire saws to slice the wafers off a block of silicon called an ingot. Sawing creates silicon shavings that wastes material, whereas this technology produces continuous thin silicon ribbons in a solution. The goal of this work is to remove any contaminating oxygen impurities in the silicon while it changes from liquid to solid, through increased understanding and better-engineered floating silicon furnaces.

Project Name: Machine Learning Accelerates Innovation in Perovskite Manufacturing Scale-Up
Awardee: Massachusetts Institute of Technology
Location: Cambridge, Massachusetts
DOE Award Amount: $300,000
Principal Investigator: Tonio Buonassisi
Project Summary: This project is using machine learning to improve the manufacturing scale-up process for perovskite PV technologies. The methodology will speed up the research and development cycle for emerging perovskite PV technologies via the machine-learning-assisted experimental design. The team will develop a framework that combines sequential machine learning and process engineering to maximize process improvements with fewer required experiments. This framework will enable rapid development of scalable deposition process for perovskite PV manufacturing.

Project Name: Advanced Perovskite Cells and Modules
Awardee: National Renewable Energy Laboratory       
Location: Golden, Colorado
DOE Award Amount: $6,195,000
Principal Investigator: Joseph Berry
Project Summary: This core photovoltaics capability project examines critical materials, integration, and device issues required to propel the development of halide perovskite solar cells (HPSC) technologies. This project will use a scientific approach to understand the roadblocks and risks associated with commercializing HPSC technologies, including any challenges to fully scalable manufacturing and long lifetime field operation. This project will focus on stability research to better understand mechanisms that cause degradation and failure in HSPC and develop device stability acceleration factors that can be applied across relevant halide perovskite materials for PV and associated device architectures. This work will be device-centric but have a materials-driven emphasis to work towards overcoming the efficiency, stability, and scalability challenges preventing HPSC from reaching $0.03 per kilowatt-hour by 2030.

Project Name: Flexible Perovskite-Perovskite PV for Mobile Power Applications
Awardee: National Renewable Energy Laboratory
Location: Golden, Colorado
DOE Award Amount: $745,500
Principal Investigator: David Moore
Project Summary: The National Renewable Energy Laboratory and Swift Solar are partnering to commercialize the lab’s novel solar cell device design. The design will enable the manufacture of lightweight, flexible, and highly efficient multijunction perovskite solar cells.

Project Name: Scribe and Interface Modification for Stable Halide Perovskite Modules
Awardee: National Renewable Energy Laboratory
Location: Golden, Colorado
DOE Award Amount: $450,000
Principal Investigator: Joey Luther
Project Summary: The National Renewable Energy Laboratory will work with Tandem PV to improve stability and lifetime of perovskite photovoltaics. The project will investigate methods to protect device layers exposed by the scribing steps of monolithic interconnection, which separates thin-film cells during the module conversion process, and other coating defects. This approach could reduce degradation rates and improve overall module lifetime.

Project Name: Tandem Photovoltaic Devices
Awardee: National Renewable Energy Laboratory       
Location: Golden, Colorado
DOE Award Amount: $9,000,000
Principal Investigator: Emily Warren
Project Summary: Tandem or multijunction solar cells are able to convert sunlight to electricity with greater efficiency than single junction solar cells by splitting the solar spectrum across sub-cells with different bandgaps. Combining well-established photovoltaic technologies into a single tandem architecture holds promise for dramatically increasing total cell efficiency, but substantial development is needed to address the challenges of scaling hybrid tandems from “champion cells” to interconnected large modules. This project will fabricate tandem photovoltaic devices, focusing on a perovskite/silicon platform, assess performance and reliability, measure and model energy yield, and compare their performance and cost to industry-standard silicon PV. The objective is to demonstrate commercially relevant prototypes and understand their realistic costs, performance benefits, and trade-offs for different PV markets. Module-level concerns such as optical losses, stringing, bifaciality, and multi-cell interactions will be considered. Analysis will be performed to identify emerging tandem combinations as well.

Project Name: Investigation of Ga2O3 as a New Transparent Conductive Oxide for Photovoltaics Applications
Awardee: Ohio State University
Location: Columbus, Ohio
DOE Award Amount: $200,000                  
Principal Investigator: Tyler Grassman
Project Summary: This project explores the use of a new material, gallium oxide (Ga2O3), as a transparent conducting oxide (TCO) layer for solar cells. TCOs are a layer within a solar cell that conduct electricity on top of the light absorbing material in the solar cell, such as cadmium telluride. As a result, the conductivity of the TCO and its transparency to the full solar spectrum are critical properties for creating a TCO that’s effective. Ga2O3 has a wide bandgap which is a property of the material that makes it transparent to the full solar spectrum. This enables more light to pass through the TCO and be absorbed by the absorbing layer that converts the photonic energy into electrical energy. To determine the applicability of Ga2O3 as a TCO for PV technologies, this team will study the deposition of this material in solar cells using tools that are commonly used in the solar industry. The team will then test the resulting optical and electronic properties of the solar cell and analyze the performance of the prototype TCO.

Project Name: BioPhotovoltaics – New Paradigm Towards High-Efficiency and High-Stability Cells
Awardee: Pennsylvania State University
Location: University Park, Pennsylvania
DOE Award Amount: $160,000
Principal Investigator: Shashank Priya
Project Summary: This project is investigating novel composites of biological molecules and perovskite photovoltaic (PV) materials for designing biophotovoltaic (BPV) devices. This innovative approach will lead to increased stability and performance over traditional perovskite PV cells. The biomolecule will be able to form chemical bonds with the crystal lattice of the perovskite material, which will assist in the growth of high-quality perovskite crystal films. If successful, the project will lead to efficient (>23%) BPV devices that are stable over 5 years in ambient atmosphere.

Project Name: Identifying Impacts of Process, Precursors and Defects in Metal Halide Perovskite Solar Cells
Awardee: Princeton University
Location: Princeton, New Jersey
DOE Award Amount: $1,500,000
Principal Investigator: Barry Rand
Project Summary: In an effort to improve the energy yield and stability of metal halide perovskite photovoltaic solar cells, this project aims to improve material selection and fabrication techniques for producing these cells. The team will identify interactions that can occur in precursor solutions or at solid interfaces that result in defects, either spontaneously or under solar cell-relevant stresses such as light, heat, atmosphere, and voltage. The team will then establish targeted strategies and processes to mitigate perovskite cell degradation by selecting optimal precursor solutions and creating robust absorbers needed to make these high-efficiency solar cells.

Project Name: Total Characterization of Perovskite Films for Enhanced Stability 
Awardee: SLAC National Accelerator Laboratory
Location: Menlo Park, California
DOE Award Amount: $1,500,000
Principal Investigator: Kevin Stone
Project Summary: This project aims to characterize and understand the material properties that affect the efficiency and stability of metal halide perovskite (MHP) photovoltaic devices. The team will develop advanced characterization tools to determine what governs device stability and manufacturing reliability, such as X-ray technology to see how much of the films are crystalline and how much are amorphous or glassy. The team will automate the tools so they work when manufacturing is scaled up, aiming to ultimately increase module lifetime and manufacturing reliability. They will leverage insights into MHP synthesis and performance from the National Renewable Energy Laboratory and Cubic PV (formerly Hunt Perovskite Technologies).

Project Name: High-Throughput Vapor Deposition for Perovskite-Perovskite Tandem Modules
Awardee: Swift Solar
Location: Golden, Colorado
DOE Award Amount: $660,000
Principal Investigator: Joel Jean
Project Summary: Perovskite-perovskite tandem photovoltaic solar cells offer an opportunity to obtain high efficiency levels while maintaining the low-cost and high-throughput manufacturing potential enabled by thin-film perovskite materials. This team is adapting an already commercially proven vapor deposition technique and test its use with perovskites at industrial scale for the first time. This will technique could be an alternative to the widely used solution-based perovskite growth methods. The team aims to validate the vapor deposition method and produce a tandem module with an efficiency that’s greater than 25%.

Project Name: Investigation of Defect Physics for Efficient, Durable and Ubiquitous Perovskite Solar Modules
Awardee: University of California, Los Angeles
Location: Los Angeles, California
DOE Award Amount: $850,000
Principal Investigator: Yang Yang
Project Summary: In order to push perovskite solar cells closer to their theoretical limit of efficiency and durability, researchers need to better understand and control defects in the perovskite material and at the surface of the layers in the cell. These defects are the source of losses in the cell’s open circuit voltage and can cause degradation in the solar cell over time. This project is developing physical models of defect-induced types of degradation, both on the surface and in the bulk perovskite material. The team will conduct a blend of computational and experimental studies on critical defect types and densities within the perovskite material when there’s heat, light, increased voltage, or moisture present. The team will then use in-depth characterization techniques to quantify the chemical and electronic properties of defects in order to improve defect manipulation techniques that could increase perovskite cell efficiency.

Project Name: Mini-Modules Made with Monolithically Integrated All-Perovskite Tandems
Awardee: University of Colorado Boulder
Location: Boulder, Colorado
DOE Award Amount: $1,037,515
Principal Investigator: Michael McGehee
Project Summary: In collaboration with perovskite researchers at the National Renewable Energy Laboratory, this team aims to make monolithic two-terminal tandem solar cells that have a 27% efficiency level and are constructed entirely from thin-film perovskite light absorbers. This would represent a roughly 10% relative increase in power-conversion efficiency over the current best-performing single-junction perovskite solar cells.  The project will use scalable deposition methods such as slot-die coating, sputtering, chemical vapor deposition and thermal evaporation to fabricate perovskite solar cells that degrade by less than 10% after 1,000 hours of use.

Project Name: Roll-to-roll Manufacturing of Continuous Perovskite Modules
Awardee: University of Louisville
Location: Louisville, Kentucky
DOE Award Amount: $849,216
Principal Investigator: Thad Druffel
Project Summary: Perovskite solar cell research focuses on making the material that absorbs photons, called the absorber, more durable and efficient. This project investigates the applicability of low-cost roll-to-roll manufacturing techniques for perovskite modules. The team will employ rapid deposition and annealing techniques, which are the processes used to deposit the absorber layer onto a substrate and then heating and cooling it to toughen the absorber. The team will then study the performance of the absorber layer and use the same techniques on the remainder of the device layers. The team aims to use these techniques to create a high throughput manufacturing process for perovskite modules in a commercial roll-to-roll facility.

Project Name: Semi-Transparent, Reliable and Efficient Scalable Organic Solar Cells for Building Integrated Applications
Awardee: University of Michigan
Location: Ann Arbor, Michigan
DOE Award Amount: $1,300,000
Principal Investigator: Stephen Forrest
Project Summary: Organic photovoltaics (OPV) are a solution for semi-transparent building integrated photovoltaics for windows, building facades, and rooftops. This project is producing organic solar cells with a 15% power conversion efficiency that are 50% transparent and have a projected 20-year lifetime for building-integrated photovoltaics. This would nearly double the increase in performance compared to typical power-conversion-efficiency values at similar levels of optical transparency. The team will also use its roll-to-roll film-growth technology to continue to improve manufacturing yields and the scalability of OPV.

Project Name: Scalable Manufacturing of Efficient Perovskite/Silicon Tandem Modules
Awardee: University of North Carolina at Chapel Hill
Location: Chapel Hill, North Carolina
DOE Award Amount: $1,500,000
Principal Investigator: Jinsong Huang
Project Summary: This project focuses on increasing solar cell efficiencies by using both perovskite and silicon as the semiconductors in a photovoltaic cell. This team will design and test a 6-inch by 6-inch silicon perovskite tandem cell using an inexpensive high-throughput process capable of producing 5,000 wafers per hour in a solar cell fabrication facility. This process uses a low-cost blade coating process to apply the relevant perovskite layers to make the tandem cells, leading to a lower capital expenditure required to implement this process in existing or new solar cell fabrication facilities. The resulting tandem solar cell could reach an efficiency over 30%, as compared to 25% for silicon.

Project Name: High-speed Solution Printing and Photonic Curing of Transparent Electrodes on Plastics  
Awardee: University of Texas at Dallas
Location: Richardson, Texas
DOE Award Amount: $800,000
Principal Investigator: Julia Hsu
Project Summary: This project uses innovative materials design and a novel annealing method—photonic curing—to facilitate high-throughput, low-cost manufacturing of transparent electrodes on plastic substrates enabling cost-competitive perovskite solar cells with 18% power conversion efficiency. The goal is to produce a high-performance transparent conducting layer  on polyethylene terephthalate (PET), a common plastic used to make items like water bottles. The project team will perform lab-scale validation, sheet-scale upscaling, and roll-to-roll demonstration of manufacturability.

Project Name: Toward Low-Cost, Efficient and Stable Perovskite Thin-Film Modules
Awardee: University of Toledo
Location: Toledo, Ohio
DOE Award Amount: $2,900,000
Principal Investigator: Yanfa Yan
Project Summary: This project is developing high-efficiency perovskite mini modules and investigating deposition techniques that can be scaled up for high-speed manufacturing. The team will work with First Solar, which has world-leading expertise in industrial thin-film photovoltaic (PV) manufacturing, degradation testing, and predictive lifetime modeling. To test reliability, the team will develop accelerated stress-testing methods that can detect what degrades perovskite modules outdoors.

Project Name: Ultra-High Efficiency and Stable All-Perovskite Tandem Solar Cells
Awardee: University of Toledo
Location: Toledo, Ohio   
DOE Award Amount: $1,100,000                               
Principal Investigator: Yanfa Yan
Project Summary: This team is developing processes and strategies to fabricate high efficiency and stable perovskite-perovskite thin-film tandem solar cells. The team aims to develop efficient wide-bandgap perovskite cells with high open circuit voltages for the top layer of the tandem while also developing efficient low-bandgap cells for the bottom layer. The team will then develop efficient interconnecting semiconductor layers with low optical and electrical losses and study potential ways that these perovskite-perovskite tandem cells could degrade over time. The team will use this information to develop approaches to mitigate instability issues in perovskite-perovskite tandem cells in order to increase lifetime and lower costs, with the aim of developing a cell with greater than 25% efficiency.

Project Name: In-situ Characterizations of Microstructural Degradation of Perovskite Solar Cells
Awardee: University of Utah
Location: Salt Lake City, Utah
DOE Award Amount: $200,000
Principal Investigator: Heayoung Yoon
Project Summary: To understand how perovskite solar cells degrade, this project team is developing ways to measure the electronic properties of features in perovskite absorbers while the device is exposed to high temperature, bright light, and other potential causes of damage. These features include the surface of the solar cell; the bulk of the grains, or tiny perovskite crystals, in the solar cell; and the grain boundaries, or the spaces between the grains in the cell.

Project Name: Approaching the Radiative Efficiency Limit in Perovskite Solar Cells with Scalable Defect Passivation and Selective Contacts
Awardee: University of Washington
Location: Seattle, Washington
DOE Award Amount: $1,250,000
Principal Investigator: David Ginger
Project Summary: This project focuses on using low-cost techniques to develop perovskite solar cells that approach the radiative efficiency limit in order to reach the maximum possible performance for these cells. The radiative efficiency limit of solar cells is the limit at which no photons absorbed by the cell are lost to heat producing defects. In order to achieve this goal, researchers must better understand defects in the perovskite material and invent new ways to passivate, or deactivate, these defects. In order to improve the efficiency and lifetimes of perovskite solar cells, it’s important to be able to passivate defects that arise in low-cost manufacturing environments. The team will use novel optical and microscopic probes to provide insight into the defects currently produced during perovskite cell production and then develop scalable layers to add to the solar cell to passivate these defects.

Project Name: CIGS Technology Advancement via Fundamental Modeling of Defect/Impurity Interactions
Awardee: University of Washington
Location: Seattle, Washington
DOE Award Amount: $700,000
Principal Investigator: Scott Dunham
Project Summary: Copper indium gallium selenide is a promising material for high performance, low-cost thin-film photovoltaics. In order to improve conversion efficiency and lower manufacturing costs, researchers need to better understand interactions between mineral impurities and native defects, as well as how both couple to alloy ordering and phase separation within these cells. This team is using density functional theory calculations to predict distributions of defects and defect complexes, estimate reaction and diffusion rates, and perform simulations to predict alloy, impurity, and defect ordering. The team will test the resulting model and process in order to optimize device performance, reliability, and cost.

Project Name: Forecasting Perovskite Photovoltaic Device Performance using Dark-Field Imaging and Machine Learning
Awardee: University of Washington
Location: Seattle, Washington
DOE Award Amount: $1,500,000
Principal Investigator: Hugh Hillhouse
Project Summary: Photovoltaic (PV) devices with combinations of low-cost, high power conversion efficiency, and low degradation rates are necessary in order to achieve a levelized cost of electricity of $0.03per kilowatt-hour (kWh). Hybrid perovskites (HPs) are expected to have sufficiently-low expected cost and sufficiently-high power conversion efficiency to achieve this goal, though long-term stability is a concern due to the existence of several degradation pathways. This project is developing accurate forecasting models for device performance lifetime of state-of-the-art all-perovskite tandem solar cells using machine learning models that will account for device-to-device variation. The forecasting model will predict the tandem power-conversion efficiency under standard operating conditions, which will be validated with new conformal prediction methods, along with comparison to in-the-field device monitoring. The forecasting models will also provide important data that will improve device architecture and encapsulation strategies to extend the performance lifetime.

Project Name: Machine Learning Assisted Enhancement of Perovskite Stability and Performance
Awardee: University of Washington
Location: Seattle, Washington
DOE Award Amount: $1,500,000
Principal Investigator: Hugh Hillhouse
Project Summary: High photovoltaic power conversion efficiency devices with low year-over-year degradation rates, like hybrid perovskites, have the potential to lower costs if their stability and phase segregation can be improved. In order to better determine the maximum open-circuit voltage and photocurrent a hybrid perovskite solar cell is capable of generating, this team is developing photoluminescence (PL) video methods that reveal the role of micron-scale spatial PL heterogeneity and millisecond-time-scale PL intensity flickering in material degradation and phase segregation. When combined with large composition libraries and different testing environments, they yield enormous data sets. The team plans to mine this data with advanced machine-learning algorithms in order to generate a predictive model of degradation for perovskite solar cells. 

Project Name: Bringing High-Efficiency Silicon Solar Cells With Heterojunction Contacts to Market with a New, Versatile Deposition Technique
Awardee: Arizona State University
Location: Tempe, Arizona
DOE Award Amount: $1,000,000
Principal Investigator: Zachary Holman
Project Summary: This project aims to enable manufacturable, high-performance silicon solar cells through an innovative deposition technique that will improve cell efficiency and reduce equipment and material costs. In order to arrive at the ideal contact stack that’s transparent and can easily be made with inexpensive tool and precursors, the silicon community has been experimenting with stacking new materials within solar cells. The team will develop and use a gas-flow sputter source that will be coupled with an aerosol-driven assembly tool. The team aims to use the tool to deposit any type of metal oxide carrier-selective layer or transparent conductive oxide layer with full control of the material composition, without damaging the underlying layers. 

Project Name: Direct Metallization with Reactive Inks – Assessment of Reliability and Process Sensitivities
Awardee: Arizona State University
Location: Tempe, Arizona
DOE Award Amount: $1,400,000
Principal Investigator: Owen Hildreth
Project Summary: This project is investigating the material and growth properties of reactive metal inks in order to explore their potential use in the metallization of silicon solar cell. The research team seeks to radically change the cost structure of the cell by dramatically reducing silver consumption. This technique is of particular importance to temperature sensitive devices, such as heterojunction architectures, where the low processing temperatures of reactive inks offer a significant advantage and alternative metallization methods are currently expensive.

Project Name: Operando X-ray Nanocharacterization of Polycrystalline Thin Film Modules
Awardee: Arizona State University
Location: Tempe, Arizona
DOE Award Amount: $859,253
Principal Investigator: Mariana Bertoni
Project Summary: This project is developing an X-ray-based characterization framework that enables nanoscale module mapping at different length scales for cadmium telluride and copper indium gallium selenide cells under a variety of operating conditions. The project team is using several lab-based mapping and synchrotron-based techniques coupled with the collection of IV curves in custom-designed stages capable of handling different temperatures, atmospheres, and illumination conditions. This work will allow for a better understanding of the nanoscale composition and structural changes that occur during module operation. It will also enable the development of proposed pathways to reduce the rates of the associated degradation, which will enable higher module efficiencies, longer warranties, and lower degradation rates.

Project Name: Photovoltaic Plant Predictive Maintenance Optimization under Uncertainties Using Probabilistic Information Fusion
Awardee: Arizona State University
Location: Tempe, Arizona
DOE Award Amount: $750,000
Principal Investigator: Hao Yan
Project Summary: This project uses artificial intelligence and machine learning methods to develop algorithms that will optimize operation and maintenance of photovoltaic (PV) power plants by detecting and classifying anomalies, predicting failures, and scheduling maintenance activities. Predictive maintenance is important to maintain the long-term financial performance of solar PV plants and reduce downtime. Real-time monitoring data such as power output, temperature, and weather information can be used to identify the common fault class patterns using a hierarchical generative model and probabilistic information fusion framework in the sensor level and system level. This project will use the power plant operated at Arizona State University and Arizona Public Service as the case study to demonstrate the proposed technology for predictive maintenance.

Project Name: PV Foundry: Increasing Manufacturing Capabilities in the U.S. by Developing Passivated Contact PV Technology
Awardee: Arizona State University
Location: Tempe, Arizona
DOE Award Amount: $2,650,000
Principal Investigator: Christiana Honsberg
Project Summary: This project leverages the advanced cell and module prototyping facilities at Arizona State University to support U.S. companies that want to prove the viability of new photovoltaic (PV) technologies but don’t have equipment that can fabricate them. The foundry will focus on post–passivated emitter rear contact silicon solar cell and module technologies, which are built to capture more light on the back surface of the cell and are expected to grow to dominate the manufacturing landscape. It will allow users to improve process steps and designs and work to reduce production costs.

Project Name: SonicWafering™ of III-V Substrates for High-Efficiency Cells: A Path to <$0.50/W
Awardee: Arizona State University
Location: Tempe, Arizona
DOE Award Amount: $2,120,000
Principal Investigator: Mariana Bertoni
Project Summary: Creating the base, or substrate, of a solar cell typically requires sawing silicon blocks, but using sound waves instead of a metal saw results in less material waste and improves the lifetime of the substrate. This team is working to prove the viability of a sonic wafering process that uses low temperatures and intense sound waves to carefully and accurately remove completed gallium arsenide solar cells from the top surface of a thick wafer to reuse III-V substrates, so named for the semiconductor materials in groups III and V of the periodic table. This work would significantly reduce the cost of producing high-quality III-V substrates, which is one of the costliest components of this type of solar cell.

Project Name: Understanding Defect Activation and Kinetics in Next Generation CdTe Absorbers
Awardee: Arizona State University
Location: Tempe, Arizona
DOE Award Amount: $510,000
Principal Investigator: Mariana Bertoni
Project Summary: This project aims to improve the understanding of defects in cadmium telluride (CdTe) photovoltaic solar cells by revealing new information about the way defects form when the semiconductor is treated with chlorine or doped as part of the fabrication process. Doping and chlorine treatment in CdTe solar cell fabrication are both critical processes but advances to these processes often cancel each other out, which results in the open circuit voltage of the solar cell remaining stagnant. The team will focus on using nanoscale X-ray imaging techniques and novel spectroscopic approaches to visualize the formation of defects during chlorine treatment under various conditions. The team will use this information to optimize the process to make these cells, improving open circuit voltage and helping to drive down costs.

Project Name: Back-Contact Interface Engineering for Higher Efficiency CdTe PV
Awardee: Colorado State University
Location: Fort Collins, Colorado
DOE Award Amount: $3,200,000
Principal Investigator: James Sites
Project Summary: The rear contact is one of the performance-limiting components of cadmium telluride (CdTe) solar cells, and it will likely need to be dramatically improved for CdTe is to reach monocrystalline silicon cell efficiencies. This project team is working to identify the best materials to use to make high-quality passivated rear contacts for thin-film CdTe solar cells, and possibly bifacial modules, pushing CdTe technology closer to 25% efficiency while preventing power loss.

Project Name: Doping CdTe and CdSeTe for Higher Efficiency
Awardee: Colorado State University
Location: Fort Collins, Colorado
DOE Award Amount: $750,000
Principal Investigator: Walajabad Sampath
Project Summary: This project aims to significantly enhance the voltage and efficiency of cadmium telluride and cadmium selenium telluride solar cells through p-type doping with group-V atoms. Colorado State University, with help from multiple partners including the National Renewable Energy Laboratory and First Solar, will focus on using arsenic to increase the density of holes in the absorber by two orders of magnitude. The team will seek to increase the cell voltage by 100 millivolts and improve cell efficiency from 3% to 22%. The key to success will be the activation of a major portion of the dopant atoms so that they each contribute a hole to the absorber while minimizing the recombination that commonly results from nonactivated dopant atoms. The team will ensure that its cell-fabrication steps are compatible with low-cost, large-scale manufacturing.

Project Name: Development of ~ 25% Efficient Double Side Screen Printed Poly-Si/SiOx Passivated Contact Solar Cells
Awardee: Georgia Institute of Technology
Location: Atlanta, Georgia
DOE Award Amount: $1,500,000
Principal Investigator: Ajeet Rohatgi
Project Summary: Very few contact layers for silicon (Si) photovoltaic (PV) cells can achieve efficiency higher than 25% at a lower cost than Passivated Emitter and Rear Contact (PERC). One promising candidate to surpass PERC are Tunnel Oxide Passivated poly-Si SiOx contacts (TOPCon), but currently these contacts can only be used on the back side of Si PV cells rather than both sides. This is because the TOPCon layer absorbs some sunlight before it reaches the active PV material, which decreases the cell’s efficiency. It is also currently expensive to screen-print TOPCon layers on very thin poly-Si layers. Recently, the project team succeeded in making a double-sided screen-printed TOPCon Si PV cell with ≥ 22% efficiency. The team will use these methods to screen-print TOPCon layers on thin (≤ 20 nm) poly-Si layers. They will also improve the TOPCon layer itself by decreasing charge recombination and incorporating oxygen to expand its bandgap, which will reduce the amount of sunlight it absorbs. If successful, the team will produce a low-cost, commercial-ready ≥ 24.5% efficient Si PV cell with double-side screen-printed TOPCon layers.

Project Name: Technology Development for Greater than 23% Efficient P-PERC Solar Cells
Awardee: Georgia Institute of Technology
Location: Atlanta, Georgia
DOE Award Amount: $700,000
Principal Investigator: Ajeet Rohatgi
Project Summary: This project is developing key technologies to achieve commercial-size passivated emitter and rear contact (PERC) cells with a 23% efficiency rate from a current rate of about 22%. The team will integrate multiple technologies to create the solar cell, including spatially controlled doping profiles, passivated rear contacts, advanced annealing treatments, and high-resolution screen printing. Together, these technologies will reduce carrier recombination rates in the junction region, at the back surface field, and at the interfaces within each contact while also minimizing front shading and rear light absorption. To improve solar cell performance, the team will use the same process on n-type silicon to produce rear junction n-type cells with spatially controlled front surface fields.

Project Name: Field-Effect Passivation by Desired Charge Injection into SiNx Passivation in Crystalline-Silicon Solar Cells
Awardee: Inert Plasma Charging LLC
Location: Tempe, Arizona
DOE Award Amount: $1,120,000
Principal Investigator: Jeong-Mo Hwang
Project Summary: This team developed a low-cost plasma-charging technology that can be used for field-effect passivation in crystalline silicon solar cells and to increase efficiency. The technology uses an inexpensive inert gas plasma that does not cause film deposition or corrosion inside the chamber during charging and does not require regular cleaning of the chamber. To enable the commercial use of this tool, the team will work to mitigate the loss of injected charges during the high-temperature metal-firing process and increase the stability of injected charges by mitigating optical and electronic degradation pathways. These efforts have the potential to enable contact deposition that matches the high performance of aluminum oxide while maintaining the low production costs of conventional passivation materials.

Project Name: Refinement of the Floating Silicon Method: A Low-Cost Monocrystalline Silicon Wafer Manufacturing Process
Awardee: Leading Edge Crystal
Location: Somerville, Massachusetts
DOE Award Amount: $1,250,000
Principal Investigator: Nathan Stoddard
Project Summary: This project is developing kerfless, single crystal wafer manufacturing technology that enables a projected all-in cost reduction of at least 25% in solar panel manufacturing. This project also supports the production of sample wafers for process development and product demonstration with industry partners.

Project Name: Exploiting Fixed Charge at Selective Contacts for Silicon Photovoltaics
Awardee: Lehigh University
Location: Bethlehem, Pennsylvania
DOE Award Amount: $200,000                  
Principal Investigator: Nicholas Strandwitz
Project Summary: In a silicon solar cell, thin metal lines are applied to the silicon absorber that serve as electrical contacts in the solar cell. These electrical contacts must efficiently conduct current out of the absorber layer to boost solar cell performance. However, sometimes there are undesirable barriers that form between the two layers that hinder the efficient conduction of current. This team is investigating the use of alumina oxide as a fixed charge layer in the solar cell. They will apply it between the absorber layer and the front contact of the solar cell to mitigate the effect of these barriers. This project will use atomic layer deposition to grow alumina and the contact layers in the lab and will use a variety of techniques to reveal the structural, chemical, and interfacial electronic properties of the material in order to determine the suitability of this strategy for commercial PV applications.

Project Name: Advanced Thin-Film PV Core Capability (Cadmium Telluride)
Awardee: National Renewable Energy Laboratory       
Location: Golden, Colorado
DOE Award Amount: $9,000,000
Principal Investigator: Matthew Reese
Project Summary: Cadmium telluride (CdTe) is the current cost-leading photovoltaic (PV) technology, directly competing with silicon PV at scale, even when manufactured in the United States. The efficiency of CdTe remains much below the detailed balance limit due to its low photovoltage. To improve upon this voltage deficit, improvements need to be made in carrier concentration, minority carrier lifetime, and interface recombination. Using a new defect chemistry with group V doping instead of copper has been identified as a viable route using single crystal systems. This project will implement this new defect chemistry in scalable, polycrystalline, thin-film CdTe devices with tasks focusing improvements to the front interface, absorber, and rear interface.

Project Name: Cracked Film Lithography for Metal Grids in CdTe Modules
Awardee: National Renewable Energy Laboratory
Location: Golden, Colorado
DOE Award Amount: $250,000
Principal Investigator: Christopher Muzzillo
Project Summary: Cracked film lithography (CFL) is a low-cost method for patterning metal grids. CFL consists of coating a suspension of nanoparticles on a substrate. As the suspension dries, it forms cracks that are used to pattern subsequent metal deposition, which is followed by lift-off of the crack template. This leaves behind a metal grid with ca. 2 um wide wires and 20 um space between wires—advantageous properties for transparent conduction applications. In particular, these small wire spacings can alleviate series resistance in CdTe modules, allowing transparent conduction architectures that have historically been unattainable.

Project Name: Development and Application of Voltage Loss Analysis for Advanced Thin Film PV
Awardee: National Renewable Energy Laboratory
Location: Golden, Colorado
DOE Award Amount: $1,700,000
Principal Investigator: Darius Kuciauskas
Project Summary: Thin-film solar cell efficiency and reliability improvements require voltage-loss analysis to include band-tail effects, contact selectivity, and correlations between interface chemistry and electro-optical (EO) properties. This project is developing and validating experimental and computational characterization tools to be used in collaborative research with industry and academic labs to increase efficiency and reliability of thin film solar cells. A special focus of the project will be on  understanding how device and material electro-optical properties derive from the chemical composition. Device models and modeling codes will integrate experimental data with semiconductor band structure, defect models, and solar cell optics.

Project Name: Electrically Detected Magnetic Resonance for Identifying Defects in Wide Range PV Devices and Materials
Awardee: National Renewable Energy Laboratory
Location: Golden, Colorado
DOE Award Amount: $750,000
Principal Investigator: Paul Stradins
Project Summary: This project is developing and adapting a very sensitive magnetic resonance technique – Electrically Detected Magnetic Resonance (EDMR) – to identify atomic origins of performance- and reliability-limiting defects in photovoltaic (PV) cells and modules. This includes identification and mitigation of defects in the forefront silicon PV technologies, and defect identification in degraded modules. The project will also establish a state-of-the-art EDMR capability at the lab. EDMR, with extreme sensitivity for identifying microscopic origins of performance and reliability-limiting defects, will advance new high-performance technologies in mainstream and emerging PV.

Project Name: Hands-On Photovoltaics (PV) Experience Core Capability               
Awardee: National Renewable Energy Laboratory       
Location: Golden, Colorado
DOE Award Amount: $245,000
Principal Investigator: Adele Tamboli
Project Summary: Hands-On PV Experience (HOPE), is a one-week summer school program held at the National Renewable Energy Laboratory (NREL) each year to train graduate student PV researchers in PV fundamentals, as well as specific cell technologies and techniques in measurement and characterization. The program brings in students from across the United States and their faculty advisors for an in-depth, intensive program that includes hands-on lab experiences in solar cell fabrication and testing. This program aims to train future PV researchers and increase collaboration among the students, faculty, and staff at NREL. To improve the program in FY22-24, the team will use previously-recorded content to streamline the workshop, increase outreach to groups that have not collaborated with the lab, and increase module- and systems-level content.

Project Name: III-V PV Cell Core Capability          
Awardee: National Renewable Energy Laboratory       
Location: Golden, Colorado
DOE Award Amount: $4,000,000
Principal Investigator: Myles Steiner
Project Summary: This project focuses on reducing the costs of III-V photovoltaic modules for domestic energy production applications, through research into multijunction cell fabrication that incorporates substrate reuse. The project will investigate techniques to grow high-efficiency tandem solar cell structures on low-cost substrates by both MOVPE and HVPE growth platforms. We will continue our efforts to engage with industry stakeholders by collaborating, where possible, on other substrate removal technologies as well. At the end of the three-year project, our main goal is to demonstrate ≥30% GaInP/GaAs tandem cells on an inexpensive substrate.

Project Name: Passivated Contacts for Direct Wafer® Product
Awardee: National Renewable Energy Laboratory
Location: Golden, Colorado
DOE Award Amount: $150,000
Principal Investigator: David Young
Project Summary: This project highlights a new PV product that consists of a thin-oxide passivated contact (TOPcon) solar cell and applies two NREL technologies described in U.S. Patent No. 9,911,873, Hydrogenation of Passivated Contacts and U.S. Patent Application Serial No. 15/890,172, Doped Passivated Contacts, to a silicon wafer made through advanced, kerfless manufacturing. Synergy between the higher efficiency potential of TOPcon and the ultra-low cost kerfless wafers grown using the Direct Wafer process developed by 1366 Technologies, Inc. (1366) will accelerate the market adoption of both by delivering the lowest LCOE in the PV industry.

Project Name: PV Cell and Module Performance Testing Core Capability              
Awardee: National Renewable Energy Laboratory       
Location: Golden, Colorado
DOE Award Amount: $9,300,000
Principal Investigator: Nikos Kopidakis
Project Summary: This core photovoltaics capability project maintains the National Renewable Energy Laboratory’s PV Cell and Module Performance Laboratory and provides access to PV performance measurements and best practices to U.S. universities, national laboratories, and the Solar Energy Technologies Office. Through its primary reference cell calibrations, this laboratory maintains the PV peak watt rating for the United States. This work assures that U.S. consumers, installers, and PV project developers can have confidence in the power ratings of the PV modules they purchase, enabling a more robust U.S. PV industry. This project also provides a world record of PV performance measurements, which is essential for tracking the progress of PV research and development.

Project Name: Silicon PV Core Capability              
Awardee: National Renewable Energy Laboratory       
Location: Golden, Colorado
DOE Award Amount: $8,250,000
Principal Investigator: Paul Stradins
Project Summary: This project is developing silicon-based photovoltaic (PV) cell research and process engineering. The team will research concepts related to polycrystalline silicon/silicon dioxide passivated contacts, cell design and processing, and fundamental loss mechanisms in single crystalline wafers made by the Czochralski (Cz) process. The project aims to provide fundamental understanding and innovative solutions to the PV community in these areas to improve p-type passivated contacts, to explore lean processing of high-efficiency cells, and to help solve PV energy loss due to wafer lifetime degradation. This project also supports collaborative research efforts with academia and industry that advances the knowledge base of fundamental materials science, physics, and chemistry of silicon-based PV technologies.      

Project Name: Solar Radiation Research Lab (SRRL)
Awardee: National Renewable Energy Laboratory
Location: Golden, Colorado
DOE Award Amount: $3,600,000
Principal Investigator: Manajit Sengupta
Project Summary: The Solar Radiation Research Laboratory (SRRL) is a world-leading solar calibration and measurement facility and maintains the World Radiation Reference, which is essential for traceable and accurate measurements of solar radiation at all solar generation facilities. The Baseline Measurement System at SRRL provides a high-quality record of solar irradiance and surface meteorological conditions. SRRL capabilities are used to develop improved methods for the calibration of solar radiometers as well as new standards, models, and advanced instrumentation and methods for operating solar measurement stations. The SRRL datasets are also critical for validation of new models and datasets such as the National Solar Radiation Data Base. Research and development of solar radiation measurement systems and resource modeling techniques are essential for advancing the scientific basis for producing reliable resource data.

Project Name: Improved Solar Cell Performance and Reliability through Advanced Defect Characterization and Growth Studies
Awardee: Ohio State University
Location: Columbus, Ohio
DOE Award Amount: $1,086,000
Principal Investigator: Aaron Arehart
Project Summary: Copper indium gallium selenide (CIGS) photovoltaic solar cells experience defects that reduce efficiency but researchers have been unable to eliminate these defects. If resolved, efficiency could improve as much as 4% from approximately 19% to approximately 23%. This team is connecting the measured defects to their physical sources using chemical and nanostructural techniques and other photoluminescence-based techniques. Using advanced, physics-based modeling, the team will identify and test CIGS growth conditions of the absorber layer in order to improve cell performance, lower device instabilities, and lower degradation rates that could improve reliability and lower the levelized cost of energy.

Project Name: PV Performance Modeling Core Capability               
Awardee: Sandia National Laboratories            
Location: Albuquerque, New Mexico
DOE Award Amount: $3,600,000
Principal Investigator: Joshua Stein
Project Summary: This Core Capability project supports a variety of improvements to photovoltaic (PV) performance models, creation of an energy rating approach and datasets for the United States, development of a model validation framework, and support for the open-source modeling package, pvlib-python. The project will also continue to support the activities and resources of the PV Performance Modeling Collaborative and activity leadership in the IEA PVPS Task 13 working group. The objective of this project is to increase the value of PV performance models by improving their functionality, demonstrating and quantifying their validity, and offering a wide range of stakeholder engagement opportunities.

Project Name: A New Low-Temperature Approach for Efficient and Low-Cost Group V Doping in CdTe Thin Film Solar Cells
Awardee: University of Alabama
Location: Tuscaloosa, Alabama
DOE Award Amount: $300,000
Principal Investigator: Feng Yan
Project Summary: This project is developing a new method to improve the performance of cadmium telluride (CdTe) solar cells by incorporating group V elements as dopants to modify its electrical properties. The novel low-temperature method will introduce the group V dopants separately from the main CdTe deposition process, which lowers cost and gives greater control over the distribution of the dopants in the CdTe film. If successful, the method will improve efficiency and decrease cost of commercial CdTe modules.

Project Name: Microdroplet Electrospray Localized Laser Printing and Sintering of Nanoparticles for Passivated, Carrier-Selective Contacts
Awardee: University of Central Florida
Location: Orlando, Florida
DOE Award Amount: $200,000
Project Summary: This project enables the printing of silver contacts on silicon solar cells with very little thermal energy use, through a scalable technology called a nanoparticle electrospray laser deposition (NELD). NELD will deposit silver microdroplets on the base of a silicon solar cell, then fuse the nanoparticles together with a laser, a process known as sintering. This project will lower costs and improve cell performance.

Project Name: In-Situ Antimony Doped Polycrystalline CdTe Films for Simplified Cell Processing and Maximized Energy Yield
Awardee: University of Delaware
Location: Newark, Delaware
DOE Award Amount: $2,000,000
Principal Investigator: William Shafarman
Project Summary: This project is advancing cadmium telluride (CdTe) solar cell open circuit voltage and reliability through antimony doped CdTe cells. The team will conduct theoretical defect calculations, defect analysis, and modeling to simplify cell fabrication and improve cell performance and reliability. The project results will reduce the levelized cost of electricity for solar energy by reducing module processing steps and increasing reliability over deployment time.

Project Name: Novel n-type Device Architectures to Achieve 1 Volt VOC in Thin Film CdTe Cells
Awardee: University of South Florida
Location: Tampa, Florida
DOE Award Amount: $645,000                  
Principal Investigator: Chris Ferekides
Project Summary: Cadmium telluride (CdTe) solar cells are a low cost thin-film technology that has achieved commercial success in the solar market. To expand the opportunities for CdTe technologies, this project will explore a new cell design which starts with n-type CdTe instead of p-type CdTe commercially used today. This new approach, could enable higher efficiency levels than the CdTe cells currently being mass produced. The team uses industrially relevant deposition techniques to demonstrate that the fabrication of n-CdTe solar cells is possible at scale with a target efficiency of 25%, an increase of 2% (absolute) from current world record CdTe solar cells.

Project Name: Investigating Local Carrier Dynamics in PERC Patterned CdTe Solar Cells
Awardee: University of Utah
Location: Salt Lake City, Utah
DOE Award Amount: $200,000
Principal Investigator: Heayoung Yoon
Project Summary: This project is developing a cadmium telluride (CdTe) passivated emitter rear contact (PERC) solar cell that comprises a patterned aluminum oxide layer and small metal contacts defined on individual grains for greater cell efficiency and power output. PERC cells are designed to capture more light on the back surface of the cell. The team will use current generated by a concentrated stream of electrons to detect any defects in the PERC design and quantify changes in physical parameters, such as the components’ efficiency, using 2- and 3-D numerical models.

Project Name: Reliability Evaluation of Bifacial and Monofacial Glass/Glass Modules with Ethylene Vinyl Acetate (EVA) and Non-EVA Encapsulants
Awardee: Arizona State University
Location: Tempe, Arizona
DOE Award Amount: $1,300,000
Principal Investigator: Govindasamy Tamizhmani
Project Summary: Photovoltaic modules with glass/glass encapsulation are expected to be more resistant to breakage and degradation than glass/backsheet modules. However, many glass/glass-module architectures continue to use ethylene vinyl acetate (EVA) as an internal encapsulant, and EVA has been linked to significant life-limiting reliability issues, including glass cracking, encapsulant delamination, and encapsulant browning. This project assesses the merits and shortcomings of glass/glass modules with EVA and non-EVA encapsulants by evaluating new and field-aged modules. The team will then evaluate the expected reliability of these modules using indoor and outdoor accelerated tests.

Project Name: Towards 50 Year Lifetime PV Modules: Glass/Backsheet vs. Double Glass
Awardee: Case Western Reserve University
Location: Cleveland, Ohio
DOE Award Amount: $1,134,000
Principal Investigator: Roger French
Project Summary: In order to enable photovoltaic (PV) modules to have a 50-year lifetime, researchers are exploring PV modules with double glass or glass/backsheet designs. To reduce degradation rates and extend the service lifetime of these high efficiency modules, researchers must better understand the operational conditions of solar cells within these modules. This project uses data from stepwise accelerated exposures and real-world PV systems to quantify the impact of PV module architecture and packaging materials on the degradation rates of double glass and glass/backsheet modules. Identifying and mitigating the degradation modes related to packaging materials and architectures for double glass and glass/backsheet modules could help to lower degradation rates toward 0.2% per year and lower the levelized cost of energy.  

Project Name: Tool for Reliability Assessment of Critical Electronics in PV (TRACE-PV)
Awardee: Clemson University
Location: North Charleston, South Carolina
DOE Award Amount: $1,600,000
Principal Investigator: Zheyu Zhang
Project Summary: Field data from photovoltaic (PV) power plant operators shows that power electronics converters are responsible for between 43% and 70% of the service calls. This project is developing a Tool for Reliability Assessment of Critical Electronics in PV (TRACE-PV), which is capable of predicting the lifetime, understanding the physics-to-failure mechanisms that manifest, and assessing the levelized cost of energy. The team will validate and demonstrate the accuracy and broad applicability of the TRACE-PV tool through accelerated life testing, field reliability data, and case studies considering different PV techniques. If successful, this project will enable PV inverter developers to understand reliability bottlenecks so they can improve the next-generation designs and evaluate new techniques’ influence on inverter reliability. Additionally, it will enable utility-scale PV operators to fairly quantify PV inverter reliability from different vendors, assess the remaining useful life of inverters under operation, and schedule maintenance in advance.

Project Name: Automating Detection and Diagnosis of Faults, Failures, and Underperformance in PV Plants
Awardee: Electric Power Research Institute
Location: Palo Alto, California
DOE Award Amount: $2,000,000
Principal Investigator: Michael Bolen
Project Summary: Using machine learning and developing algorithms, this project team is working to identify reasons for unplanned maintenance events at utility-scale solar photovoltaic (PV) plants and differentiate them from power fluctuations due to causes that do not require on-site maintenance, like weather or module degradation. By analyzing the continuous energy-production data stream coming from utility-scale PV arrays, this technology can eliminate false alarms that are sent to PV system owners and operations and maintenance firms. This would decrease the labor required to review underperformance, lower the levelized cost of PV electricity, and increase energy output.

Project Name: DOE PV Fleet Performance Data Initiative
Awardee: National Renewable Energy Laboratory
Location: Golden, Colorado
DOE Award Amount: $5,250,000
Principal Investigator: Chris Deline
Project Summary: This project leverages photovoltaic (PV) data to develop models and understanding of the field performance of existing and new technologies. The research team will report on field performance and degradation rates for high-efficiency silicon and more conventional technologies, develop automated analysis techniques to quantify system performance, refine the RdTools software toolkit to apply standard and validated analysis techniques to partner data, and inform data quality assurance by other software tools. Additionally, the team will collaborate with large-scale fleet owners to publish performance details for a major cross-section of deployed U.S. systems and disseminate findings and data. Improved analysis and reporting of PV field performance increases the certainty of owners and financiers that systems will perform as expected.

Project Name: DuraMAT 2
Awardee: National Renewable Energy Laboratory
Location: Golden, Colorado
DOE Award Amount: $18,000,000
Principal Investigator: Teresa Barnes
Project Summary: This project manages the DuraMat Consortium, which brings together DOE national lab and university research capabilities with the photovoltaic (PV) and supply-chain industries to accelerate a sustainable, just, and equitable transition to zero carbon electricity generation by 2035 through the five core objectives: development of a central data resource for PV modules, multi-scale and multi-physics modeling, disruptive acceleration science, forensic tools for fielded modules, and materials solutions for more durable, reliable, and resilient modules. DuraMAT leverages the decades of experience, expertise, and world-class facilities at the national laboratories to create a “one-stop-shop” for timely solutions to critical barriers limiting module reliability and durability. DuraMat 2 will identify which materials and packaging designs will enable high energy yield modules with the potential for 50-year lifetimes and identify long-term degradation mechanisms and wear out failures.

Project Name: PV Reliability Core Capability: R&D to Ensure a Scientific Basis for Qualification Tests and Standards
Awardee: National Renewable Energy Laboratory       
Location: Golden, Colorado
DOE Award Amount: $15,000,000
Principal Investigator: Ingrid Repins
Project Summary: This core capability project is performing research and development that leads to science-based tests and standards that can better ensure PV system reliability and quality. The team will design and perform accelerated stress tests on PV products and then correlate the results with successes and failures of PV products in the field. Testing will focus on the module package—including the glass and frame, interconnection devices, and solar cells—and the micro-characterization of both failed and healthy modules to help improve test accuracy and predictive ability. The new tests will help PV system owners better predict long-term safety and energy generation of different products while lowering the cost of PV electricity by extending the lifetime of PV modules.

Project Name: PV Proving Grounds Core Capability         
Awardee: Sandia National Laboratories            
Location: Albuquerque, New Mexico
DOE Award Amount: $6,400,000
Principal Investigator: Bruce King
Project Summary: This core capability project conducts field research to better understand how PV systems function under real-world environmental operating conditions. Core field laboratories are located at the Photovoltaic (PV) Systems Research Laboratory at Sandia and the Outdoor Test Facility. These two sites maintain similar outdoor capabilities and are supported by complimentary indoor module characterization laboratories. The PV Proving Grounds leverages independently managed remote sites in Nevada, Florida, and Michigan to enable research in a variety of extreme climate zones within the United States. Collaborative field research in partnership with U.S. industry will validate new technologies and accelerate product development. Long-term observation of fielded PV systems, selected for novelty and technical diversity, will aid in assessing non-linear degradation, emerging failure modes and correlating observations with accelerated testing. The project will also carry out independent assessments of emerging PV technologies, including novel PV modules, monitoring systems, and balance of systems components. The performance data from this project will be made available to the PV industry and U.S. companies will be able to directly interact with the national labs, giving them access to national experts and PV module and system performance assessment tools.

Project Name: A Data-Driven Approach to Real-World Degradation of Backsheets
Awardee: Underwriters Laboratories
Location: Northbrook, Illinois
DOE Award Amount: $1,350,000
Principal Investigator: Kenneth Boyce
Project Summary: The backsheet of a solar photovoltaic module is the backing of the module. In combination with the front glass sheet, the backsheet helps to seal the PV module from the outside world. The backsheet is typically made of multiple layers of various types of polymers, a type of plastic, and can degrade over time from climate conditions, making its design an important predictor for how long a solar module can last in the field. However, current accelerated tests for backsheet degradation and the lifetime performance of the module have limitations. This team employs a data-driven approach to analyze backsheet degradation for modules in the field in order to better understand the real-world environmental stresses of airborne pollution, solar irradiance, water, temperature, and abrasion on module performance. The team will use a large sample size to model and quantify the variance in degradation rates and link these to the backsheet materials being studied. This information will help inform a variety of stakeholders in the solar industry and could enable the development of more accurate standards for PV modules.

Project Name: Characterization of Contact Degradation in Crystalline Silicon PV Modules
Awardee: University of Central Florida
Location: Cocoa, Florida
DOE Award Amount: $1,581,926
Principal Investigator: Kristopher Davis
Project Summary: This project is developing a highly automated metrology solution that can non-destructively extract the series resistance and dark current of individual cells encapsulated within a photovoltaic (PV) module with minimal uncertainty for both parameters using calibrated electroluminescence imaging. This metrology can be used in reliability and durability evaluations to accelerate cycles of learning and to help develop new technologies and integrate them into high-volume manufacturing.

Project Name: Gaining Fundamental Understanding of Critical Failure Modes and Degradation Mechanisms in Fielded Photovoltaic Modules via Multiscale Characterization
Awardee: University of Central Florida
Location: Orlando, Florida
DOE Award Amount: $2,000,000
Principal Investigator: Kristopher Davis
Project Summary: This project applies multiscale characterization methods to field exposed photovoltaic (PV) modules to link observed performance degradation to specific loss mechanisms and, ultimately, to root causes. This research will be carried out on a very large and diverse population of modules to ensure statistical relevance. The team will perform multiple iterations of down-selection beginning with large-scale analysis of time-series, current-voltage data, followed by the application of both traditional and more novel on-site characterization methods. The analysis will be used to select modules for further characterization in a controlled lab setting, then to make assessments on the most likely root cause of the observed failure modes and degradation mechanisms. From those modules, individual regions of interest will be identified for targeted materials characterization to provide final confirmation of the root cause.

Project Name: LCOE Reduction through Proactive Operations of PV Systems
Awardee: University of Central Florida
Location: Cocoa, Florida
DOE Award Amount: $1,189,000
Principal Investigator: Herbert Seigneur
Project Summary: This project is developing a new monitoring system for characterizing fielded photovoltaic (PV) modules in order to provide greater certainty and detail in fielded energy output and degradation rates over their lifetimes using a central inverter. New methods for data analysis and interpretation algorithms are under development in order to detect degradation trends and mechanisms in the fielded systems. Additionally, the project is developing a model to examine the effects that different resolution PV monitoring systems have on the levelized cost of electricity from utility-scale plants based on their design, size, location, environmental considerations, and expected system lifetime.

Project Name: Maturing Solar PV Racking and Module Mounting Critical Bolted Joint Technologies for LCOE Reductions and Increased Reliability
Awardee: Lawrence Berkeley National Laboratory
Location: Berkeley, California
DOE Award Amount: $1,897,000
Principal Investigator: Gerald Robinson
Project Summary: This project lays the foundational steps needed to move toward highly robust bolted joints in photovoltaic (PV) module racking and mounting, a critical and often overlooked component of solar technologies. Bolted joints lack the technological maturity exhibited in comparable industries to deliver low-cost and highly reliable solutions that are critical for further advancement of the industry. By utilizing well-established methods and tools, this research effort will fill knowledge gaps through structured interviews of key stakeholders, modeling and lab testing of common bolted joints. The project will then develop a technical guidance document backed by empirical evidence targeting product engineers and standards committees.

Project Name: Advanced Diagnosis and Accelerated Testing of Balance of System Components for Utility Scale PV Installations
Awardee: National Renewable Energy Laboratory
Location: Golden, Colorado
DOE Award Amount: $1,500,000
Principal Investigator: David Miller
Project Summary: This project studies the durability of balance-of-system components, specifically wire harnesses (cable jackets) and connectors within the power transmission chain. The research team will collect failed samples from utility PV installations to investigate the failure modes and the related enabling practices occurring in today’s PV systems. Samples will be studied using accelerated stress testing to aid understanding of the component durability relative to its application. Component-and material-focused failure analysis will be conducted to advise the PV industry. In-depth characterization will be applied selectively to field-and artificially aged-samples, to gain scientific understanding of the structural, chemical, electrical, mechanical, and thermal properties enabling degradation.

Project Name: Quantifying Uncertainty in PV Energy Estimates
Awardee: National Renewable Energy Laboratory
Location: Golden, Colorado
DOE Award Amount: $570,000
Principal Investigator: Janine Keith
Project Summary: The goal of this project is to establish a set of best practices, or consensus methods, for quantifying uncertainty in estimates of energy generation from PV systems. The research team is working to establish what sources of uncertainty must be considered, clarify their definitions and metrics, determine which sources are the biggest drivers of uncertainty, and provide a computationally efficient framework for combining different sources of uncertainty that is flexible enough to accommodate substitutions of data or methods when better information is available.

Project Name: Enhanced Convection for Higher Module and System Efficiency
Awardee: Portland State University
Location: Portland, Oregon
DOE Award Amount: $1,000,000
Principal Investigator: Raul Cal
Project Summary: This project is developing new solar photovoltaic (PV) modules and solar system-scale designs that promote a minimum 40 percent increase of the convective heat transfer coefficient. This reduces the operating temperature of PV panels and leads to a higher annual energy yield and a potentially significant increase in the reliability of PV modules over time. Extensive modeling and early-stage experimentation is underway to determine the dynamics of air flow needed to produce vortex generation and flow channeling effects and to reduce overall thermal heterogeneity geographically across the array.

Project Name: Single-Axis Tracker Reliability and Performance Improvement
Awardee: Sandia National Laboratories
Location: Albuquerque, New Mexico
DOE Award Amount: $2,000,000
Principal Investigator: Daniel Riley
Project Summary: This project combines Sandia’s research strengths and long-standing experience in the photovoltaic (PV) industry to improve the reliability, performance, and market maturity of single axis tracker (SAT) systems. The research team will work with U.S.-based SAT manufacturers to improve the relevance of qualification standards to horizontal SATs, which are most prevalent and provide the lowest levelized cost of energy (LCOE) in the solar industry today. The team will also develop new performance data evaluation tools and sensor systems that aid system owners and operators in predicting and preventing failures of tracking systems. Additionally, the team will develop algorithms to optimize tracking of SAT systems to capture more energy in diffuse lighting and low sun angle conditions. New, publicly available performance models for optimized system design and performance validation will be made available to the public.

Project Name: Snow: Increasing the Resilience of Photovoltaic Systems in Northern Latitudes
Awardee: Sandia National Laboratories
Location: Albuquerque, New Mexico
DOE Award Amount: $1,600,000
Principal Investigator: Laurie Burnham
Project Summary: The vulnerability of photovoltaic (PV) systems to extreme weather, including heavy seasonal snowstorms, has raised increasing concern among solar industry stakeholders, ranging from utilities dealing with generation losses to asset owners wanting predictable performance, to insurers and investors concerned about the performance risks of snow shading and the reliability risks of snow loading. This project aims to quantify snow losses across a range of technologies and system designs to increase the overall efficiency of PV systems installed at northern latitudes. The data generated will inform product development, improve installation designs and practices, and generate more accurate performance models, giving stakeholders greater confidence in levelized cost of energy (LCOE) calculations and the life expectancy of PV plants in northern regions of the United States.

Project Name: Vulnerability Assessment and Risk Reduction Strategies for PV System Connectors
Awardee: Sandia National Laboratories
Location: Albuquerque, New Mexico
DOE Award Amount: $1,850,000
Principal Investigator: Laurie Burnham
Project Summary: Photovoltaic (PV) connectors are the lifeblood of PV systems, enabling the seamless flow of electrons along a string of modules and into an inverter. Despite their importance, connectors can fail, as when the build-up of debris and/or moisture increases their electrical resistance, or when substandard materials create an arc fault, or a combination of both. This project aims to conduct a comprehensive, assessment of connector reliability in the US, focused on (1) quantifying the prevalence and diversity of failure mechanisms; and (2) developing best practices and tools to reduce rates of degradation and   failure. This effort is both timely and important. Despite the criticality of connectors, little is known about the operational health of deployed connectors nor about the composition and manufacturing quality of most connectors on the market. Downward economic pressures on the manufacturing end, and handling and installation methods on the deployment end, and preliminary work by Sandia, suggest that connectors are an under-recognized weak link in the PV reliability chain.

Project Name: PVInsight Phase 2
Awardee: SLAC National Accelerator Laboratory
Location: Menlo Park, California
DOE Award Amount: $3,000,000
Principal Investigator: Bennet Meyers
Project Summary: This project builds on the work and experience of the PVInsight project and addresses modern data challenges in the residential, commercial, and utility sectors of the photovoltaic (PV) solar industry. The research team aims to develop data science tools to enable cost-effective, fleet-scale operations and maintenance for all PV systems, inclusive of those systems that have lower data quality, are not well modeled, and are lacking reliable environmental data. The team will utilize a signal-processing framework for analyzing PV performance signals, which enables the analysis of unlabeled time-series data.

Project Name: Power Electronics-Based Self-Monitoring and Diagnosing for Photovoltaic Systems
Awardee: Virginia Polytechnic Institute and State University (Virginia Tech)
Location: Blacksburg, Virginia
DOE Award Amount: $300,000
Principal Investigator: Bo Wen
Project Summary: This project is developing a self-monitoring and diagnosing technology for photovoltaic (PV) plants that is based on the power electronics they already use. This technology will enable the power electronics in a PV system, such as power optimizers and inverters, to actively test the system, measure its response to these tests, and detect any changes in the PV systems components to continuously assess their health and reliability. This project will reduce system hardware and installation costs by self-monitoring and diagnosing issues in PV systems.