Semi-transparent organic solar cells with high visible transmission enabled by a transparent wide-bandgap donor

摘要

The reported semi-transparent organic solar cells (ST-OSCs) are commonly based on a middle bandgap donor and narrow bandgap acceptor blend, for example, the PTB7-Th:Y6 blend. However, the strong absorption of PTB7-Th in the visible region hinders the further improvement of average visible transmission (AVT) for the ST-OSCs. Here we report a new kind of all-small-molecule ST-OSCs based on TAPC:Y6 blend. The used donor TAPC has little absorption in the visible region, which is beneficial for attaining high transparency. The optimized ST-OSCs based on TAPC:Y6 blend realize a power conversion efficiency of 3.01%. Importantly, a high AVT of 47.99% is achieved for this kind of ST-OSCs, much higher than those of reported ST-OSCs. The proposed TAPC: Y6 ST-OSCs also have a good color perception, whose CIE 1931 coordinates are (0.292,0.313) and color rendering index is 94.5.