High‐Throughput Computing Guided Low/High Index Optical Coupling Layer for Record‐Performance Semitransparent Organic Solar Cells

Abstract Semitransparent organic solar cells (ST‐OSCs) can be made in different colors, allowing light to pass through, and yet absorb enough visible and near‐infrared (NIR) light to generate electricity. However, it remains a challenge to achieve high performing ST‐OSCs over the two competing indexes of power conversion efficiency (PCE) and average visible transmittance (AVT). This work reports an effort to develop record‐performance ST‐OSCs using a low/high index optical coupling layer (OCL) and a 2D photonic‐structured antireflective (AR) coating. High‐throughput optical screening is used to improve the understanding of OCL structure−performance relationships and the predicting of NIR absorption enhancement for ST‐OSCs. The concurrent use of a low/high index Na 3 AlF 6 (170 nm)/ZnS (110 nm) OCL, identified among about 200 thousand simulated device configurations and a 900 nm pitch‐sized 2D photonic‐structured AR coating, fabricated using nanoimprint lithography, enables the record‐performance ternary PM6:BTP‐eC9:L8‐BO‐based ST‐OSCs, achieving simultaneously a record‐high PCE of 15.2%, a high AVT of 32%, an impressive light utilization efficiency of 4.86%, and a favorable color‐rendering index of 82. The results of the ST‐OSCs demonstrated in this work provide an attractive option for a plethora of applications in self‐powered greenhouses and building‐integrated photovoltaic systems.