Semitransparent organic solar cells with high light utilization efficiency and color rendering index

Semitransparent organic solar cells (ST-OSCs) have garnered considerable attention as promising renewable energy technology for integrating photovoltaics into buildings. However, there is a trade-off between power conversion efficiency (PCE) and average visible transmittance (AVT), which hinders the achievement of a high light utilization efficiency (LUE). In this study, we propose a valuable method to address this challenge by replacing the transparent top electrode, Ag, with a 20 nm layer of Au. The ST-OSCs based on the 20 nm Au electrode demonstrate superior exciton extraction, more efficient charge collection, and higher color-rendering index (CRI) due to their smoother surface, higher conductivity, and enhanced visible light transmittance, resulting in a significantly higher PCE of 13.67% and an enhanced AVT of 30.17%, contributing to a high LUE of 4.15%. Additionally, optically transparent dielectric layers, applied on the front and back sides of the ST-OSCs to further boost performance, delivered an impressive LUE of 4.93%, with PCE and AVT values reaching 14.44% and 34.12%, respectively. Notably, the champion ST-OSCs also exhibited a favorable CRI value of 93.37. These achievements represent the best-performing ST-OSCs to date with both high LUE and CRI and hold significant implications for the prospective commercialization of ST-OSCs.