Towards Standardization of Accelerated Stress Testing Protocols for Metal-Halide Perovskite Photovoltaic Modules

Metal-Halide Perovskite (MHP) photovoltaic (PV) modules are at the cusp of commercialization. One major hurdle that remains is establishing confidence in long-term field performance and durability of MHP modules. A lot of progress has been made in addressing many performance stability issues in MHP cells and modules; however, in the absence of established protocols for MHPs, many of the studies have been conducted using the International Electrotechnical Commissions 61215-series (IEC61215) of standardized tests. IEC61215 lays down requirements for the design qualification of terrestrial photovoltaic modules suitable for long-term operation in open- air climates and test results are not construed as a quantitative prediction of module lifetime. While some of the testing protocols outlined by IEC61215 are likely to be relevant to MHPs and do provide some insight to potential degradation mechanisms, they should not be used to infer any estimation of durability or field performance without a more rigorous understanding of how those test conditions affect the MHP and whether those conditions are even relevant. In addition, counterpart field-exposure and a thorough analysis of the degradation pathways introduced by external stressors will be needed to validate any accelerated stress testing conditions. Here I will discuss an initial accelerated stress testing protocol that can be used as the foundation for the development of a standardized test procedure for qualification of commercial MHP modules. We apply the protocol to different MHP module architectures to identify the critical degradation pathways that will inform future testing development. In addition, the modules are exposed to outdoor environments such that a cross- examination with indoor results can be used to verify the relevance of the indoor stress conditions. This work is part of the recently established Perovskite PV Accelerator for Commercializing Technologies, PACT, program.