Highly thermally stable non-fullerene organic solar cells: p-DTS(FBTTh2)2:P(NDI2OD-T2) bulk heterojunction

Abstract

Because long-term solar cell stability may be influenced by morphological reorganization, we investigated the effect of thermal annealing on bulk heterojunction solar cells comprised of p-DTS(FBTTh2)2:P(NDI2OD-T2) (3:1). Our results indicate that the p-DTS(FBTTh2)2) compound with lower diffusion kinetics enables to stabilize the blend morphology at high temperature, leading to high thermal stability of a p-DTS(FBTTh2)2:P(NDI2OD-T2) solar cell device. Therefore, The p-DTS(FBTTh2)2:P(NDI2OD-T2) solar cell indicates highly thermally stable bulk heterojunction device as retaining 70% of its original power conversion efficiency value after heating at 180°C over 20h. These results indicate that p-DTS(FBTTh2)2:P(NDI2OD-T2) is a promising BHJ system for practical use in non-fullerene OSCs.