Ternary Strategy Enabling High-Performance Organic Solar Cells with Optimized Film Morphology and Reduced Nonradiative Energy Loss

摘要

Ternary strategy has been demonstrated to be an effective way to improve powerconversion efficiency (PCE) of single-junction organic solar cells (OSCs). Herein,high-efficiency ternary OSCs are fabricated based on the PBDB-T:DO-2F binarysystem and acceptor IDTT-OB with asymmetric side chains as the third component.The introduction of nonfullerene acceptors (NFAs) IDTT-OB as a thirdcomponent can efficiently increase the compatibility of the ternary system, reducethe crystallinity of DO-2F, optimize the blend film morphology, improve thecharge transport and collection, suppress the bimolecular recombination, andreduce the nonradiative energy loss (ΔE_(nonrad)). Finally, the PBDB-T:DO-2F:IDTTOB-based ternary device exhibits a high PCE of 14.09% with Voc of 0.87 V, Jsc of21.47mA cm~(-2), and fill factor of 75.70%, which is about 30% higher thanthe corresponding PBDB-T:DO-2F- and PBDB-T:IDTT-OB-based binary devices.Meanwhile, the ternary device also achieves a very low ΔE_(nonrad) of 0.22 eV. Thiswork indicates that the ternary strategy can effectively optimize morphology ofactive layer, reduce nonradiative energy loss, and further improve photovoltaicperformance of OSCs.