5-Chlorobenzoxazole as solid additive for efficient organic solar cells

Adding solid additives to the active layer is a simple and efficient method to adjust the morphology of the active layer to obtain appropriate phase separation, thus improving the organic solar cell device performance. We found a 5-Chlorobenzoxazole molecule as a solid additive to PM6:Y6 system, which increased the filling factor from 66.2 % to 71.0 % and the PCE from 14.8 % to 16.1 %. The results indicate that 5-Chlorobenzoxazole can interact with Y6, thus optimizing the morphology of the active film, enhancing the ability of charge extraction, and further improving FF and PCE.