초록 |
Recently, polymer–fullerene based bulk heterojunction solar cells, which contain blends of PTB7 and PC71BM, have been widely studied due to exhibiting high power conversion efficiency and well-defined nanomorphology. Because of the short exciton diffusion pathway in organic thin films, the optimization of PTB7:PC71BM BHJ with optimized morphology is very important between the donor and acceptor. In order to increase nanoscale phase separation, the chemical additives of 1,8-diiodooctane (DIO) have been used in PTB7:PC71BM blend systems. However, the mechanism studies of DIO in BHJ solar cells and its effectiveness on device stability are unclear. In this study, we fabricated polymer solar cells based on PTB7:PC71BM BHJ with various DIO concentrations to investigate not only correlation between device performances and different morphologies, but also the influence of additives on device stabilities. |