Engineered charge transport layers for improving indoor perovskite photovoltaic performance

The developing Internet of Things market is attracting the indoor photovoltaic (IPV) as an essential power source. Perovskite photovoltaics (PPVs) are a fascinating candidate for IPV in solution-processable photovoltaics. Recent developments in PPVs can deliver power conversion efficiency (PCE) up to 25% outdoor (AM 1.5 G) and over 40% under indoor (1000 lux) light. The selection of charge transport layers (CTLs) has played an essential role in improving PPVs indoor performance. Herein, formamidinium-caesium-based mixed-cation (FACsPb(I,Br)₃) PPV devices are fabricated, and evaluated their outdoor and indoor performances by changing the different CTL combinations such as PTAA-PCBM and SAM-C₆₀. Outdoor PCEs were 13.76% and 15.27% achieved for PTAA-PCBM and SAM-C₆₀-based devices, respectively. Meanwhile, under LED (4000 K) 1000 lux, the PCEs were 26.32% and 31.92% for PTAA-PCBM and SAM-C₆₀-based PPV, respectively. The short circuit current (J _sc) (116.8–122.5 µA cm⁻²) and fill factor (FF) (0.724–0.817) were the main parameters which improved for SAM-C₆₀-based devices under indoor light. This study points to the importance of CTL combination and indicates the promising potential of SAM-C₆₀ interlayers in PPV indoor applications.