Improved efficiency of bulk heterojunction polymer solar cells by doping with iridium complex

摘要

To study the effect of iridium complexes on performance of polymer solar cells, we report the ternary bulk heterojunction (BHJ) polymer solar cells (PSCs) by doping an iridium complex material of bis (1-phenyliso-quinoline) acetylacetonate iridium(III) [Ir(piq)(2)acac] into the conventional active layer of poly(3-hexylthio-phene) (P3HT) and [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM). The results show that the power conversion efficiency (PCE) of P3HT:PC71BM based ternary devices is improved from 2.99% to 4.44% by doping 1 wt% Ir(piq)(2)acac, which is benefited from the enhanced exciton harvesting by Forster resonance energy transfer (FRET) from Ir(piq)2acac to P.3HT and optimized self-organized morphology within ternary blends.