| 초록 |
Photomultiplication-type organic photodiodes (PM-OPDs) rely on acceptor molecules for both charge separation and efficient gain generation. Herein, we design and synthesize a new non-fullerene acceptor by introducing thienylenevinylene (TV) groups into the conventional ITIC structure. The resulting TV-ITIC acceptor has not only extended π-conjugation length, which leads to lower energy bandgap as well as deeper lowest unoccupied molecular orbital (LUMO) level, but also increased volumetric portion of the aliphatic chain, which improves the miscibility with the donor polymer semiconductor, P3HT. All of these photophysical properties are beneficial for efficient exciton separation, electron trapping, and charge injection abilities of PM-OPDs. Because of such synergetic contributions of TV-ITIC to the photomultiplication mechanism, the resulting optimized PM-OPD exhibits a high external quantum efficiency (EQE, ＞74,000%) and a large specific detectivity (＞ 1012 Jones). |
