The high-performance organic solar cells with an improved efficiency and stability by incorporating environmental biomaterial astaxanthin

Biomaterials are a new kind of photoelectric materials, which have many advantages. Using biomaterials to adjust the photoelectric properties of active layer in organic solar cells (OSCs) is a new strategy for the preparation of high-performance OSCs. In this work, we add environment-friendly and pollution-free biomaterial astaxanthin (AST) into binary PBDB-T:ITIC system to fabricate the high-efficiency ternary OSCs for the first time. The result show that the addition of AST can not only enhance the crystallization of PBDB-T and ITIC, the absorption intensity of active layer and charge transfer, but also prolong the lifetime and diffusion length of exciton in OSCs. Moreover, there exists the Förster resonant energy transfer (FRET) between energy donor AST and the energy accepter (PBDB-T), which promotes the generation of excitons. Therefore, by adding 0.1 wt% AST, the power conversion efficiency (PCE) of ternary OSCs is obviously increased from 10.27% to 12.07% for PBDB-T:ITIC system. In addition, the ternary OSCs shows higher device storage stability due to its stable morphology and crystallization. This work shows that the clean and pollution-free biomaterial AST can effectively improve the performance of OSCs, which paves the way for the development of environmentally friendly OSCs with high efficiency and stability.