On October 15, 2021, the U.S. Department of Energy Solar Energy Technologies Office (SETO) released the Performance Targets for Perovskite Photovoltaic (PV) Research, Development, and Demonstration Programs Request for Information (RFI) for public response and comment. The RFI sought feedback from industry, academia, research laboratories, government agencies, and other stakeholders on efficiency, stability and replicability performance targets for perovskite PV devices that could be utilized to align community efforts, ensure relevance of potential future funding programs, and accelerate technical and commercial development and de-risking of perovskite technologies.
The RFI included proposed device performance targets for power conversion efficiency (PCE), area, stability, and sample sizes, and included the following questions:
- Do you feel all the proposed targets are relevant and necessary to proving technology performance of perovskite PV devices? If not, please specify why not.
- What changes or additions, if any, would you make to the proposed performance targets to improve their relevance and usability?
- Are there any specific tests, protocols, or targets that would be difficult for your organization to evaluate, require additional equipment, or place a large burden on your organization?
- DOE is considering using these targets to evaluate applicant readiness for manufacturing RD&D programs – when do you anticipate your organization would be able to meet the targets as written?
A total of 11 RFI responses were received and reviewed, including 6 from the perovskite and solar industry, 3 from national laboratory organizations, and 2 from academic institutions. This summary presents aggregated information from all RFI responses, revised performance targets, and clarification on potential utilization by SETO.
Download the RFI summary document or read the findings below.
Please note that unless explicitly stated, the U. S. Department of Energy (DOE) is not communicating an opinion or viewpoint about any of the responses described below, but rather is publishing an RFI response summary and performance targets so that the public may also benefit from information received by DOE.
Overall Device Performance Targets
For commercial viability, perovskite PV devices will need to demonstrate competitive or improved performance against current commercial PV technologies in areas such as production cost, durability, power density, energy yield, and levelized cost of electricity. While long-term targets are necessary, short- and medium-term targets are useful to the perovskite research and development (R&D) community. These targets can align research directions and goals, ensure that future funding programs are relevant, and accelerate technical and commercial development and de-risking of perovskite technologies. The SETO-funded Perovskite PV Accelerator for Commercializing Technologies (PACT) Validation and Bankability Center will aid in refining these targets.
SETO developed proposed device performance targets to evaluate the commercialization potential of perovskite prototypes, and included these in the RFI to solicit feedback on them. The table below summarizes revised device performance targets that incorporated this feedback. These targets include factors such as efficiency (by device type), durability tests, sample requirements such as number of devices, preconditioning requirements, minimum module size, and ratio of tested area to total area. The original proposed performance targets can be found in the full RFI summary document.
Table: Performance Targets to Evaluate Commercialization Potential of Perovskite Devices
Power Conversion Efficiency1 by Device Configuration
18% for single junction devices
24% for perovskite-perovskite tandem devices
27% for hybrid tandem devices (perovskite-other PV material)
Total Module Area2
At least 500 cm2 with at least 4 interconnected cells
Pass selected standard International Electrochemical Commission (IEC) and International Summit on Organic Photovoltaic Stability (ISOS) module quality tests with <10% performance loss per test3
6 months of continuous outdoor testing with <3% performance loss overall and <1% performance loss over the final 3 months4
>1 kW total capacity
At least 20 modules for outdoor testing5
- Average of tested devices, measured after at least 10 kWh/m2 of exposure to outdoor or AM1.5 light for preconditioning (To be updated as the PACT center develops test protocols)
- Tested area must be > 75% of total module area
- IEC 61215 Module Quality Tests (MQT) and ISOS-L-2 tests used to assess durability. The PACT center (or other independent laboratory) will choose representative devices to test from the available samples. Standard sampling protocols may not be followed due to available sample population sizes. Test overview:
- MQT 10 – Ultraviolet (UV) light preconditioning test: 15 kWh/m2, 60°C
- MQT 11 – Thermal cycling test: 50 cycles, −40°C to +85°C
- MQT 13 – Damp heat test: 1000 h at +85°C, 85% RH
- MQT 21 – Potential induced degradation test: IEC TS 62804-1 +85°C, 85% RH at maximum system voltage for 96 hours
- ISOS-L-2 – Light-soaking: 1000 h, 1 sun AM1.5, +75 °C, ambient environment
- Conducted by the validation center and calculated by averaging the top-performing 90% of devices
- Devices will be assigned to accelerated or outdoor testing by the PACT center or other independent laboratory
These targets will likely evolve with increased understanding of how to enable manufacturing and deployment of perovskite PV at the gigawatt scale. These targets are not necessarily applicable for all perovskite PV research, development, and deployment activities. They do not directly address commercialization pathways outside of terrestrial power generation, and they do not represent a “finish line” which will definitely lead to commercially viable devices. Instead, these targets are intended to help establish confidence and manage risk for manufacturing and commercialization programs as perovskite technologies and companies mature and expand.
Given SETO priorities and generally supportive responses, SETO intends to focus on optimizing a single set of targets and clarifying their potential usage. SETO also intends to revise these targets as needed. However, some respondents proposed alternatives to a single set of shared performance targets, including different sets of targets for different stages of development, waiting to set targets, and eliminating targets.
Respondents generally supported setting performance targets for the three device configurations proposed (single junction perovskite, perovskite-perovskite tandem, hybrid perovskite tandem). However, several suggested adding bifacial devices. No specific targets for bifacial devices were proposed, but respondents indicated that bifacial technologies are increasing in market share for incumbent technologies and are likely to be relevant to perovskites. The current targets do not exclude bifacial devices but don’t set specific targets for them, in line with SETO’s goal of setting broadly applicable targets when possible.
Feedback on PCE targets was mixed. Some groups supported increasing the targets, up to 22% PCE for single junction and 28% for hybrid tandems, while some supported decreases, as low as 23% for hybrid tandems. The proposed increases tended to be linked to proposals for smaller required device areas.
There were multiple questions about the use of “Total Area PCE”, which was a concern given edge effects for non-optimized device fabrication. “Aperture Area PCE” was proposed as an alternative to resolve this issue.
There were also multiple responses questioning whether PCE was the best metric. Energy yield was proposed as a more relevant metric, since perovskites are more temperature-sensitive than silicon or cadmium telluride technologies. This means that modules with identical PCEs as measured at standard testing conditions might have quite different operational PCEs, as modules in the field tend to operate at much higher temperatures than test conditions. The respondents indicated that a lower standard PCE for perovskites might be acceptable, as operational energy yield could still exceed incumbent technologies.
Module Area Targets
In general, respondents indicated interest in reduced module area requirements, though some indicated support for the proposed value. The alternative proposed sizes were as small as 100 cm2, but the most common proposal was for 225 cm2. This would align with a standard 150 mm by 150 mm device area, similar to standard silicon solar cells. The rationales for the proposed reductions centered around equipment availability and throughput. Some groups indicated that the proposed size was not on their current scaling roadmap and would impose an additional burden to acquire relevant tools. Multiple groups indicated that the metallization steps were the primary concern in creating larger devices, with either a lack of capability to support the proposed size or a throughput issue that would cause resource balancing challenges.
Additionally, there were some concerns about relevance of the size for alternative and initial markets. Most groups that proposed size reductions were willing to increase overall device count requirements or include process yield targets.
Durability and Sample Testing Targets
Respondents generally supported performing a subset of the proposed testing protocols. There were concerns with the ability of each entity to conduct the full range of testing. Additionally, it was proposed to change the title to “Durability” or “Reliability” rather than “Stability.”
Groups indicated a lack of confidence that the proposed light presoaking procedure was sufficient and relevant. Multiple suggestions around output requirements and similar requirements were made, as well as proposals to defer defining this protocol pending initial PACT recommendations on this topic.
A general, repeated suggestion was to reduce the number of tests to minimize burden. Given the current state of perovskite technologies, groups felt that tests directly targeting acceleration of device failure modes (mainly light, heat, cycling, and bias) were most immediately relevant. Suggestions were made to include light soaking at elevated temperature, similar to ISOS protocols, and to expand the reverse bias/partial shading testing.
Responses to the outdoor testing proposal varied. Some groups supported extending the requirement to a full year at minimum to ensure that annual variability was captured, as well as requiring multiple sites to capture variations in climate. Other groups indicated that the test duration was too long relative to their innovation cycles. There were also concerns about the success value proposed, primarily due to potential burn-in or similar behaviors that might lead to a larger initial drop, followed by more stable behavior.