Mitigation of parasitic leakage current in indoor perovskite photovoltaic modules using porous alumina interlayer

Abstract Indoor photovoltaics are limited by their inherently low‐photogenerated carrier density, leading to heightened carrier recombination and adverse leakage currents compared with conventional solar cells operating under 1 sun condition. To address these problems, this work incorporates a porous insulating interlayer (Al₂O₃) in perovskite devices, which effectively mitigates recombination and parasitic leakage current. A systematic investigation of the relationship between shunt resistance, photocarrier generation, and recombination at different light intensities demonstrates the effectiveness of the alumina interlayer in perovskite solar cells under low‐light conditions. Moreover, the practicability of the alumina interlayer was demonstrated through its successful implementation in a large‐area perovskite solar module (PSM). With bandgap engineering, the optimized PSM achieves a remarkable power conversion efficiency of 33.5% and a record‐breaking power density of 107.3 μW cm⁻² under 1000 lux illumination. These results underscore the potential of alumina interlayers in improving energy harvesting performance, particularly in low‐light indoor environments. image