Imec, Partners Show Outdoor Stability of Highly Anticipated Perovskite Solar Modules

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Imec, partner in EnergyVille, in collaboration with the University of Cyprus, has demonstrated long-term outdoor stability of perovskite solar modules. Mini-modules of 4 cm2, developed at imec/EnergyVille, were comprehensively evaluated over two years in real-world conditions in Cyprus, with a remarkable power efficiency retention of 78 percent after one year, which current perovskite solar modules only retain for weeks. These promising findings are among the first real-world results to address the stability issues that currently hinder perovskite solar cells from commercialization.

Over the last decade, metal halide perovskites have emerged as a promising material for next-generation photovoltaic (PV) cells, thanks to their unique optical and electronic properties. With advancements in materials and engineering, these cells have shown a rapid improvement in their power conversion efficiency (PCE).

However, stability challenges remain the primary obstacle to widespread adoption, as they degrade due to moisture, light and heat. Standard indoor testing in a controlled environment, which continuously mimics sun irradiation, only serves as a proxy for real-world performance. Environmental conditions, such as varying light, temperature and weather, impact cell performance. Despite this, only a handful of research groups have investigated outdoor performance of perovskite PV, focusing primarily on small cells rather than modules.

Over the last two years, imec conducted a comprehensive study of the outdoor performance of their perovskite PV modules. Mini-modules, measuring 4 cm2 and developed at imo-imomec Hasselt University and imec/EnergyVille in Belgium, were tested in collaboration with the University of Cyprus. The most durable modules retained 78 percent of their initial PCE after a year outdoors in Cyprus. This showcases their promising stability compared to current perovskite solar modules, which retain such outdoor efficiency for only weeks to months. Thanks to the outdoor set-up, a consistent pattern of performance degradation during the day and overnight recovery was also discovered. Additionally, the wealth of data allowed exploration with a machine learning model, which showed a strong correlation with the actual power output, highlighting its potential for future performance predictions.

“This research represents a major advancement in understanding the degradation of perovskite solar modules in real-world conditions. With further improvements of the efficiency of our mini-modules, which are designed with upscaling in mind, these findings can accelerate the path towards commercialization of this promising technology,” stated Tom Aernouts, R&D Manager at imec/UHasselt/EnergyVille.

To gain deeper insights into degradation behaviour across different climate zones, the modules will also be evaluated in the rainy climate of Brussels, the arid desert of New Mexico, and the moderate climates of Madrid and Freiburg.