The Solar Energy Technologies Office (SETO) Fiscal Year 2018 Funding Program addresses the affordability, flexibility, and performance of solar technologies on the grid. This program funds early-stage research projects that advance both solar photovoltaic (PV) and concentrating solar-thermal power (CSP) technologies and supports efforts that prepare the solar workforce for the future.
On October 23, 2018, the U.S. Department of Energy (DOE) announced $53 million in new projects to advance solar technologies. Of those projects, 31 will focus on PV research and development. On March 22, 2019, an additional $28 million in funding was announced for 25 projects, 18 of which will focus on PV research and development.
Approach
Projects in the PV research and development topic support early-stage research that increases performance, reduces costs, and improves reliability of PV cells, modules, and systems.
Projects will develop and test new ways to accelerate the integration of emerging technologies into the solar industry. These Innovative Pathway projects do not fund individual technologies along their pathway to market; instead, they focus on improving the pathway itself.
Objectives
Projects in this funding program will strengthen the innovation ecosystem across the country. Technical projects will work toward developing new technologies and solutions capable of lowering solar electricity costs for PV, while Innovative Pathway projects will work toward creating new ways to overcome technology transfer challenges.
Selectees
Project Name: Impact of Undoped Substrates on High Performance Silicon Solar Cells
Location: Tempe, Arizona
DOE Award Amount: $200,000
Cost Share: $50,000
Principal Investigator: Andre Augusto
Project Summary: This team will investigate the potential advantages of using undoped silicon wafers to make high-performance solar cells. The team will examine silicon heterojunction cell characteristics built using wafers with a range of low n- and p-type dopant concentrations and will closely observe the transition from low-level to high-level injection to better understand the device physics of these cells. These studies could impact the manufacturing yield of Czochralski-grown wafers for which dopant concentration varies along the length of the ingot and will help to better understand the effects of doping levels on light and polarization-induced degradation mechanisms. This research aims to lower the levelized cost of energy by improving PV cell and ingot manufacturing yield, silicon cell power output, and module reliability.Project Name: Multi-Messenger In-situ Tolerance Optimization of Mixed Perovskite Photovoltaics
Location: Golden, Colorado
DOE Award Amount: $200,000
Cost Share: $50,000
Principal Investigator: Xerxes Steirer
Project Summary: This project will evaluate perovskite PV degradation mechanisms involving water and oxygen exposure, electrical bias, light, elevated temperature, and the loss of volatile gases. The team will perform experiments on degraded hybrid perovskites and evaluate potential solutions to prevent degradation and power loss in perovskite solar cells. Water and gas interactions with perovskite films will be probed to reveal any relevant surface bonding, activation energies, and chemical reactions. The resulting information will further the design of highly stable perovskite materials for use in future PV modules and systems.Project Name: Comparative Life-Cycle Analysis of Scalable Single-Junction and Tandem Perovskite Solar Cell Systems
Location: New York, New York
DOE Award Amount: $200,000
Cost Share: $50,000
Principal Investigator: Vasilis Fthenakis
Project Summary: This project will investigate the life-cycle impact of lead used in perovskite solar cells, and quantify environmental and health risks related to its use while exploring lead alternatives for large-scale manufacturing. The team will conduct a comprehensive analysis of the energy and resource requirements of perovskite PV systems and manufacturing within an established life-cycle-analysis framework. The team will also examine the potential for solvent recovery and reuse and end-of-life management for perovskite solar cells to better understand its environmental impact. The results of this project will help the industry make scalable and sustainable decisions while the efficiency and stability of perovskite solar cells are improved.Project Name: Exploiting Fixed Charge at Selective Contacts for Silicon Photovoltaics
Location: Bethlehem, Pennsylvania
DOE Award Amount: $200,000
Cost Share: $50,000
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 will investigate 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 to determine the suitability of this strategy for commercial PV applications.Project Name: Investigation of Ga2O3 as a New Transparent Conductive Oxide for Photovoltaics Applications
Location: Columbus, Ohio
DOE Award Amount: $200,000
Cost Share: $50,000
Principal Investigator: Tyler Grassman
Project Summary: This project will explore 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 CdTe. 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 potential. 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: Bifacial PV Module Energy Modeling Validation Study
Location: Oakland, California
DOE Award Amount: $200,000
Cost Share: $50,000
Principal Investigator: Tara Doyle
Project Summary: Bifacial PV module suppliers are conducting their own efficiency tests in an effort to demonstrate energy gains to customers, but these tests often lack third-party review. To enable more accurate and bankable solar production forecasts for bifacial modules, this team will establish an outdoor test that compares modeled energy from bifacial models to measured energy generation in common types of ground or roof coverings. These tests will account for multiple scenarios for bifacial modules, including placement on painted flat roofs, placement in fields with low-lying vegetation, and soiling from dirt or sand. The team will publish the results of this analysis to improve modeling efforts, energy-yield estimates, and bankability for bifacial modules on the market.University of Illinois at Urbana-Champaign 1
Project Name: Controlling the Recombination Activity of Dislocations in III-V Solar Cells
Location: Urbana, Illinois
DOE Award Amount: $200,000
Cost Share: $50,000
Principal Investigator: Minjoo Lee
Project Summary: Existing III-V manufacturing methods, such as epitaxial liftoff, that attempt to reuse costly III-V and germanium substrates over many growth cycles are too expensive to enable manufacturing at scale. One way to overcome this issue is to grow them on low-cost substrates such as silicon. This team will perform the first systematic study of III-V solar cells grown on silicon surfaces decorated with beryllium, carbon, germanium, tellurium, and other impurities to identify conditions that will render dislocations and other structural defects less harmful to solar cell performance. Reducing the impact of defects would improve device performance and enable the use of low-cost growth substrates in the fabrication of high-performance III-V cells and modules.University of Illinois at Urbana-Champaign 2
Project Name: Wide-Bandgap Polycrystalline III-Vs as Transparent, Carrier-Selective Heterojunction Contacts for Silicon Photovoltaics
Location: Urbana, Illinois
DOE Award Amount: $200,000
Cost Share: $50,000
Principal Investigator: Minjoo Lee
Project Summary: This project will test visibly transparent III-V materials grown at low temperatures for use within the front contact of a silicon solar cell. The cell will have heterojunction contacts, which are state-of-the-art contacts that can efficiently extract voltage from silicon solar cells at high rates. The team will grow heavily doped layers of aluminum gallium phosphide and aluminum indium phosphide on textured silicon solar cells to explore the doping and defects within the cell. The team will then characterize the surface passivation and contact resistance of the most promising layers and make complete PV cells with the heterojunction contacts.University of Minnesota Twin Cities
Project Name: Improving Energy Yield in Photovoltaic Modules with Photonic Structures
Location: Minneapolis, Minnesota
DOE Award Amount: $200,000
Cost Share: $50,000
Principal Investigator: Vivian Ferry
Project Summary: Silicon-based PV modules operate at elevated temperatures, which can reduce the lifetime of a PV module and contribute to thermal degradation. One of the major sources of elevated temperature is the low-energy infrared light that is converted to heat within the cell. This project aims to replace the silicon nitride antireflection coating that’s used on solar cells with spectrally selective photonic structures. The new design will enable the structures to capture usable photons while rejecting those that lack the energy to produce electricity, resulting in improved energy yield for solar cells. The structures will be integrated on the top surface of the cell to avoid damage from weathering and will be fabricated with fewer layers to minimize cost.Project Name: Higher Throughput, Lower Cost Processing of Flexible Perovskite Solar Cells by Photonic Curing
Location: Richardson, Texas
DOE Award Amount: $200,000
Cost Share: $69,113
Principal Investigator: Julia Hsu
Project Summary: In collaboration with NovaCentrix, this team will apply photonic curing to the thermal annealing process needed to form and optimize the layers in a perovskite solar cell. Photonic curing can replace the lengthy, costly, and energy-intensive conventional heating methods that are not compatible with high-throughput manufacturing on flexible substrates. The goal of this project is to increase manufacturing throughput and lower manufacturing costs while maintaining the performance metrics needed to establish a clear path toward the $.03 cents per kilowatt-hour by 2030 for utility-scale solar.Project Name: In-situ Photophysical Monitors and Corrective Algorithms for Photovoltaic Film Deposition and Rapid Thermal Processing in Scalable Roll-to-Roll Manufacturing
Location: Seattle, Washington
DOE Award Amount: $198,806
Cost Share: $50,329
Principal Investigator: Devin MacKenzie
Project Summary: Low-cost, high-throughput solution processing could substantially reduce thin-film PV costs, but it requires new PV manufacturing lines using roll-to-roll processing. This project will develop and use gas flow-stabilized slot-die deposition heads and in situ, real-time optical tools to characterize the roll-to-roll deposition process used to create these PV cells. The team will use fiber-based optical probes, time-resolved photoluminescence, and light-scattering probes to better understand, for the first time, the critical phase transformations and sintering processes needed to create perovskites with roll-to-roll processing. The team will develop real-time corrective algorithms for the deposition process and use these tools to optimize roll-to-roll deposition methods for perovskites and other thin-film PV materials.Project Name: Quantum-Cutting Luminescent Coatings for High-Efficiency, Low-Cost Solar Cells
Location: Seattle, Washington
DOE Award Amount: $200,000
Cost Share: $50,000
Principal Investigator: Daniel Gamelin
Project Summary: This project will investigate the use of quantum-cutting down-conversion layers to be placed at the front surfaces of PV cells in order to remedy a major source of energy loss. The down-converting layer converts high-energy photons, which are normally reflected or inefficiently collected, into multiple lower energy photons. This enables the more efficient conversion of energy by the underlying PV material which can double the current generated by the solar cell. This project will develop and optimize quantum-cutting precursor ink formulations and large-area solution-deposition techniques. Together, these techniques will enable the integration of these high-efficiency quantum-cutting down conversion layers onto the surfaces of commercially available silicon PV cells to realize low-cost, high-efficiency PV technologies.Project Name: Preparation and Evaluation of N-type CdSeTe as an Absorber in Thin-Film CdTe PV
Location: Pullman, Washington
DOE Award Amount: $198,578
Cost Share: $49,645
Principal Investigator: John McCloy
Project Summary: The power-conversion efficiency of conventional p-type CdTe absorbers is limited by relatively poor electronic properties, including low carrier lifetime, low doping levels, and challenges with back contact formation. This project aims to produce and evaluate n-type doped cadmium selenium telluride (CdSeTe) thin films that have the potential to exceed the performance of conventional absorber layers while maintaining the low manufacturing costs inherent to thin-film-module architectures. The team will use close-space sublimation and newly developed feedstock materials, followed by heat treatments in the presence of carefully chosen gases to obtain high-quality n-type CdTeSe with the enhanced electronic properties needed to create high-efficiency thin-film solar cells.Project Name: Bringing High-Efficiency Silicon Solar Cells With Heterojunction Contacts to Market with a New, Versatile Deposition Technique
Location: Tempe, Arizona
DOE Award Amount: $1,000,000
Cost Share: $250,000
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. To arrive at the ideal contact stack that is 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: Understanding Defect Activation and Kinetics in Next Generation CdTe Absorbers
Location: Tempe, Arizona
DOE Award Amount: $700,000
Cost Share: $175,140
Principal Investigator: Mariana Bertoni
Project Summary: This project aims to improve the understanding of defects in cadmium telluride (CdTe) PV 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 of making these cells, improving open circuit voltage and helping to drive down costs.Case Western Reserve University
Project Name: Toward 50 Year Lifetime PV Modules: Glass/Backsheet vs. Double Glass
Location: Cleveland, Ohio
DOE Award Amount: $1,350,000
Cost Share: $337,500
Principal Investigator: Roger French
Project Summary: In order to enable 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 will use 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: Doping CdTe and CdSeTe for Higher Efficiency
Location: Fort Collins, Colorado
DOE Award Amount: $750,000
Cost Share: $187,500
Principal Investigator: Walajabad Sampath
Project Summary: This will 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 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.Georgia Institute of Technology
Project Name: Technology Development for Greater than 23% Efficient P-PERC Solar Cells
Location: Atlanta, Georgia
DOE Award Amount: $700,000
Cost Share: $175,000
Principal Investigator: Ajeet Rohatgi
Project Summary: This project will develop 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.Institute for Building Technology and Safety
Project Name: Application of Manufacturing Quality Management Systems to PV Design and Installation
Location: Ashburn, Virginia
DOE Award Amount: $1,490,758
Cost Share: $377,956
Principal Investigator: Richard Lawrence
Project Summary: This team will develop an independent quality management system for PV installations which is low cost and accessible to local and regional PV installers. Third-party inspections for systems can be costly and inconsistent across the industry. This team will standardize quality control processes, enable remote review of PV systems through photos and documents, and implement an industry-recognized quality scoring system for participating installers. The team will work with a broad group of industry stakeholders to define and test the software’s functionality. Through use of the product, installers will increase the quality of their projects, which will in turn increase the overall value of PV systems across their lifetime and improve investor confidence in the solar asset class over time.Project Name: Deciphering Degradation: Machine Learning on Real-World Performance Data
Location: San Francisco, California
DOE Award Amount: $1,250,000
Cost Share: $500,000
Principal Investigator: Adam Shinn
Project Summary: Degradation rates are generally assumed to be the same across all PV modules leading to market inefficiencies. kWh Analytics will build a machine-learning model using its industry-wide data repository and generation data from about 20% of America’s operating PV plants, to quantify degradation rates for PV modules and analyze the impact that various materials and components have on these rates. This will enable insurers to incorporate these insights into their insurance premium pricing, which introduces a price signal to the market that benefits modules that use high-quality materials and components.Project Name: Improved Solar Cell Performance and Reliability through Advanced Defect Characterization and Growth Studies
Location: Columbus, Ohio
DOE Award Amount: $1,500,000
Cost Share: $375,000
Principal Investigator: Aaron Arehart
Project Summary: Copper indium gallium selenide (CIGS) PV 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 will connect 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 to improve cell performance, lower device instabilities, and lower degradation rates which could improve reliability.Project Name: Identifying Impacts of Process, Precursors and Defects in Metal Halide Perovskite Solar Cells
Location: Princeton, New Jersey
DOE Award Amount: $1,500,000
Cost Share: $375,000
Principal Investigator: Barry Rand
Project Summary: In an effort to improve the energy yield and stability of metal halide perovskite PV 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: Accelerated Scaling to Rapid Open-Air Fabrication of Durable Perovskite Solar Modules
Location: San Francisco, California
DOE Award Amount: $1,496,069
Cost Share: $375,000
Principal Investigator: Reinhold Dauskardt
Project Summary: This project will fabricate and encapsulate large-area and durable perovskite solar modules using a scalable open-air processing route that validates the reliability of the cell by using accelerated testing and thin-film metrics. The team’s scalable processing of durable perovskite and inorganic transport layers provides a platform to make series-integrated high-voltage perovskite solar modules entirely in open air, eliminating unstable organic transport layers. The work will mitigate barriers to wide-scale deployment of perovskite technology, namely module manufacturing and reliability, and eventually allow PV-generated electricity to reach costs as low as $0.02 per kilowatt hour.Project Name: A Data-Driven Approach to Real-World Degradation of Backsheets
Location: Northbrook, Illinois
DOE Award Amount: $1,500,000
Cost Share: $375,000
Principal Investigator: Kenneth Boyce
Project Summary: The backsheet of a PV 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 will employ a data-driven approach to analyze backsheet degradation for modules in the field 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.University of California, Los Angeles
Project Name: Investigation of Defect Physics for Efficient, Durable and Ubiquitous Perovskite Solar Modules
Location: Los Angeles, California
DOE Award Amount: $1,000,000
Cost Share: $250,000
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 will develop 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 to improve defect manipulation techniques that could increase perovskite cell efficiency.Project Name: Quantifying and Valuing Fundamental Characteristics and Benefits of Floating Photovoltaic (FPV) Systems
Location: Cocoa, Florida
DOE Award Amount: $750,000
Cost Share: $187,500
Principal Investigator: John Sherwin
Project Summary: Floating photovoltaic (FPV) systems are PV systems that are sited directly on bodies of water. The FPV market is expected to grow globally but there’s limited research about ways to improve designs and reduce costs. This project will address key FPV research gaps through a combination of field testing and computational activities that leverage existing FPV installations to provide data and insights for design and cost analysis. Potential benefits to PV system efficiency will be assessed as well as the ecological impacts of FPV on water bodies. Tradeoffs of system designs on FPV viability in different regions, impacts of FPV systems on grid interactions and reliability, and the value of pairing FPV with energy storage systems will also be assessed.University of Colorado Boulder
Project Name: Mini-Modules Made with Monolithically Integrated All-Perovskite Tandems
Location: Boulder, Colorado
DOE Award Amount: $1,499,764
Cost Share: $375,235
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 20% 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
Location: Louisville, Kentucky
DOE Award Amount: $999,216
Cost Share: $250,459
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 will investigate 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
Location: Ann Arbor, Michigan
DOE Award Amount: $1,300,000
Cost Share: $325,474
Principal Investigator: Stephen Forrest
Project Summary: Organic photovoltaics (OPV) are an ideal solution for semi-transparent building integrated PV for windows, building facades, and rooftops. This project will produce organic solar cells with a 15% power conversion efficiency that are 50% transparent and have a projected 20-year lifetime for building-integrated PV. 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.University of North Carolina at Chapel Hill
Project Name: Scalable Manufacturing of Efficient Perovskite/Silicon Tandem Modules
Location: Chapel Hill, North Carolina
DOE Award Amount: $1,324,937
Cost Share: $334,703
Principal Investigator: Jinsong Huang
Project Summary: This project will focus on increasing solar cell efficiencies by using both perovskite and silicon as the semiconductors in a PV 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 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 of over 30%, as compared to 25% for silicon.Project Name: Novel n-type Device Architectures to Achieve 1 Volt VOC in Thin Film CdTe cells
Location: Tampa, Florida
DOE Award Amount: $750,000
Cost Share: $187,500
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 will use industrially relevant deposition techniques to demonstrate that the fabrication of n-CdTe solar cells is possible at scale with efficiencies approaching 25%, an increase of 2% from current world record CdTe solar cells.Project Name: Machine Learning Assisted Enhancement of Perovskite Stability and Performance
Location: Seattle, Washington
DOE Award Amount: $1,500,000
Cost Share: $375,000
Principal Investigator: Hugh Hillhouse
Project Summary: High PV 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. To better determine the maximum open-circuit voltage and photocurrent a hybrid perovskite solar cell is capable of generating, this team will develop 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 to generate a predictive model of degradation for perovskite solar cells.Project Name: CIGS Technology Advancement via Fundamental Modeling of Defect/Impurity Interactions
Location: Seattle, Washington
DOE Award Amount: $681,016
Cost Share: $179,090
Principal Investigator: Scott Dunham
Project Summary: Copper indium gallium selenide is a promising material for high performance, low-cost thin-film PV. 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 pair to alloy ordering and phase separation within these cells. This team will use 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 to optimize device performance, reliability, and cost.Project Name: Field-Effect Passivation by Desired Charge Injection into SiNx Passivation in Crystalline-Silicon Solar Cells
Location: Tempe, Arizona
DOE Award Amount: $1,120,000
Cost Share: $280,000
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: Diagnosing and Overcoming Recombination and Resistive Losses In Non-Silicon Solar Cells Using a Silicon-Inspired Characterization Platform
Location: Tempe, Arizona
DOE Award Amount: $1,500,000
Cost Share: $375,000
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 CdTe 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: Reliability Evaluation of Bifacial and Monofacial Glass/Glass Modules with Ethylene Vinyl Acetate (EVA) and Non-EVA Encapsulants
Location: Tempe, Arizona
DOE Award Amount: $1,500,000
Cost Share: $375,000
Principal Investigator: Govindasamy Tamizhmani
Project Summary: PV 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 will assess 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.Massachusetts Institute of Technology
Project Name: Low-Cost, High-Efficiency III-V Photovoltaics Enabled By Remote Epitaxy through Graphene
Location: Cambridge, Massachusetts
DOE Award Amount: $1,500,000
Cost Share: $375,000
Principal Investigator: Jeehwan Kim
Project Summary: This project will develop low-cost, high-throughput, and high-efficiency multijunction PV by leveraging remote epitaxy and a 2-dimensional layer transfer process that uses hybrid vapor phase epitaxy (HVPE). This manufacturing method allows the growth of defect-free single-crystalline films that can be easily separated from the substrate. The substrate, which is expensive, can be infinitely reused by copying the crystalline information from the substrate through graphene. To validate the feasibility of this method, tandem PV cells will be grown and characterized to achieve maximum power conversion efficiency levels. In addition, the HVPE technique will enable high-throughput epitaxy at low costs, helping to produce PV cells at manufacturing scale.Project Name: High-Throughput Vapor Deposition for Perovskite-Perovskite Tandem Modules
Location: Golden, Colorado
DOE Award Amount: $750,000
Cost Share: $500,000
Principal Investigator: Joel Jean
Project Summary: Perovskite-perovskite tandem PV 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 will adapt an already commercially proven vapor deposition technique and test its use with perovskites at industrial scale for the first time. This 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: Novel and Effective Surface Passivation for High-Efficiency N- and P-Type Silicon Solar Cells
Location: Newark, Delaware
DOE Award Amount: $800,000
Cost Share: $200,000
Principal Investigator: Ujjwal Das
Project Summary: Passivation of surface defects is key to achieving high-efficiency silicon solar cells. This project aims to achieve superior surface and cell performance in silicon PV by using sulfur and selenium compounds to passivate the silicon surface and enable high open circuit voltage. The team will analyze sulfur and selenium surface behavior using advanced X-ray and capacitive characterization methods for advanced cell design applications, such as p-type passivated emitter rear contact (PERC) and n-type passivated emitter rear totally diffused (PERT) structures, where voltage has traditionally been a major limiting parameter.Project Name: Ultra-High Efficiency and Stable All-Perovskite Tandem Solar Cells
Location: Toledo, Ohio
DOE Award Amount: $1,100,000
Cost Share: $275,000
Principal Investigator: Yanfa Yan
Project Summary: This team will develop 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 to increase lifetime and lower costs, with the aim of developing a cell with greater than 25% efficiency.Project Name: Approaching the Radiative Efficiency Limit in Perovskite Solar Cells with Scalable Defect Passivation and Selective Contacts
Location: Seattle, Washington
DOE Award Amount: $1,250,000
Cost Share: $312,500
Principal Investigator: David Ginger
Project Summary: This project will focus 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. To achieve this goal, researchers must better understand defects in the perovskite material and invent new ways to passivate, or deactivate, these defects. 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: Developing Socially and Economically Generative, Resilient PV-Energy Systems for Low- and Moderate-Income Communities: Applications to Puerto Rico
Location: Tempe, Arizona
DOE Award Amount: $1,229,307
Cost Share: $307,328
Principal Investigator: Clark Miller
Project Summary: The project team will work to develop innovative approaches and models to enable Puerto Rico’s low- and moderate-income (LMI) communities to better understand how they can use solar energy to improve resilience and energy affordability. The team will analyze and model different approaches for expanding solar energy access, including household, business, community, and utility-based solar solutions. Researchers will map the solar opportunity for LMI communities in Puerto Rico and conduct deeper analysis of specific representative communities.Project Name: Bringing LMI Solar Financing Models to Scale
Location: Montpelier, Vermont
DOE Award Amount: $1,103,239
Cost Share: $277,250
Principal Investigator: Warren Leon
Project Summary: There have been several pilot and small-scale efforts to tackle the challenges of financing low- to moderate- income (LMI) projects, but there hasn’t been a multi-state or region-wide initiative. This project will research three new solar program designs and associated financing models to expand and scale solar access to low- and moderate-income single-family homes, mobile homes, and multifamily homes. This project will focus on analyzing the outcomes of these newly piloted business models then, when appropriate, assessing how they could be scaled to multiple states. Specifically, the team will analyze: the Connecticut Green Bank model to serve LMI single family homeowners; the New Mexico state model to develop “PV on a pole” prototypes that can be inexpensively manufactured and installed widely at mobile homes; and the Clean Energy Group model to work with affordable housing organizations to use non-government funded loan guarantees and other strategies to finance solar and solar plus battery storage for multifamily affordable housing buildings.Project Name: Revolving Program Related Investments Energy Savings Fund
Location: Oakland, California
DOE Award Amount: $999,470
Cost Share: $2,022,801
Principal Investigator: Jake Bobrow
Project Summary: The team will design, build, test, and scale an innovative financing and project-development model that could expand PV access to low- and moderate-income Americans. The model, which incorporates new sources of capital, aims to lower solar electricity costs and reduce creditworthiness as a barrier of entry, particularly in the development of multifamily rooftop and ground-mounted community solar projects that are 50-500 kilowatts.Project Name: Accelerating Low-Income Financing and Transactions for Solar Access Everywhere (LIFT Solar Everywhere)
Location: Washington, DC
DOE Award Amount: $1,500,000
Cost Share: $375,000
Principal Investigator: Lori Michelle Moore
Project Summary: This team will assess the replicability and scalability of a variety of solar financing models that could enable greater solar access, including: a private finance option similar to a utility credit structure; a “pay as you save” structure that pays for solar with shared savings; and a credit enhancement model that leverages alternative financing like loss reserves offered through foundations, municipal authorities, or public-private partnerships. The team will analyze adoption rates and performance data from ongoing projects, with an eye toward optimizing the models for scale.International Center for Appropriate and Sustainable Technology (ICAST)
Project Name: Developing and Piloting Solar Financing Models to Expand PV Access to Low and Moderate Income Americans
Location: Lakewood, Colorado
DOE Award Amount: $999,935
Cost Share: $256,454
Principal Investigator: Ravi Malhotra
Project Summary: This team will partner with utilities, multifamily affordable housing (MFAH) projects, and private investors to create and validate an aggregated shared solar financing model. This financing model aims to reduce project costs and risks, which has prevented MFAH solar development.Project Name: Product Innovation to Increase Low-to-Moderate-Income Customers’ Adoption of Community Solar PV
Location: Cambridge, Massachusetts
DOE Award Amount: $1,500,000
Cost Share: $500,000
Principal Investigator: Stephanie Speirs
Project Summary: Approximately 77% of U.S. households cannot access rooftop solar and 40% of homes earning less than $40,000 per year only make up less than 5% of U.S. solar installations. Low- and moderate-income (LMI) households are often excluded from community solar because of information asymmetries, prohibitively high credit score requirements, and restrictive contract terms. This project aims to expand PV solar access to households by evaluating the use of an alternate credit score, previously developed by Solstice Initiative, and performing tests to understand the most suitable contract terms for different LMI customer segments. The project will explore ways to deploy alternative capital in partnership with foundations, community development financial institutions, and others to produce and pilot a suite of community and shared solar contracts that can meet the needs of LMI households. The team will then perform rigorous data analysis concerning the factors that affect the financial viability of LMI-inclusive projects. This will help to expand the solar market, lower customer acquisition costs, and increase solar affordability.