Study explores stability of flexible perovskite cells under damp heat

Researchers from the Research Organization of Science and Technology and the Department of Electrical and Electronic Engineering at Ritsumeikan University, Japan, examined the stability of flexible perovskite solar cell (PSC) modules based on methylammonium lead iodide (MAPbI3) under damp heat (DH) conditions. PSC modules were tested with barrier films that had different water vapor transmission rates (WVTR) between 5.0 × 10−3 and 7.4 × 10−1 g/m²/day at 85°C. The modules were subjected to a 2000-hour damp heat (DH) test at 85°C and 85% relative humidity. Modules with higher WVTR values showed faster degradation rates. I-V curves showed the second diode component, and surface reflectance and electroluminescence data indicated chemical decomposition of perovskite and segregation of PbI2. After 1000 and 2000 hours, samples with the lowest WVTR remained 91.5% and 84.2% efficiency, respectively. The study identified a threshold WVTR value to reduce water vapor infiltration and emphasized the impact of barrier film quality on module stability.