| 초록 |
In this study, a novel acceptor–donor–acceptor (A–D–A) triad type small molecule (SM), 5TRh-PCBM, which has oligothiophene segment as the central core and fullerene-derivatives as the end groups, is designed and synthesized for compatibilizer of fullerene-based organic solar cells. 5TRh-PCBM was added and evaluated in initial fullerene-based binary blend system (P3HT:PC61BM) and high-efficiency blend system (PTB7-Th:PC71BM), respectively. Interestingly, at appropriate ratio of 5TRh-PCBM, thermal stability of P3HT:PC61BM and PTB7-Th:PC71BM-based solar cell was improved retaining 93% and 85% of its initial power conversion efficiency at annealing condition of 150°C and 80°C for 120hr, respectively. This thermally stable tolerance is likely due to the fullerene end groups of SM which can prevent thermal diffusion of PC61BM(or PC71BM) as binder, and minimized interfacial energy at the interface between donor and acceptor. |
