High-Performance Non-Fused Wide Bandgap Acceptor for Versatile Photovoltaic Applications.

Wide bandgap non-fullerene acceptors with non-fused conjugated structures play a critical role in organic photovoltaic cells. Here, the non-fullerene acceptors named GS-OEH, GS-OC6 and GS-ISO with the optical bandgaps larger than 1.70 eV are synthesized without using the fused ring structures. Compared with GS-OEH and GS-OC6, GS-ISO exhibits much stronger crystallinity, leading to a smaller energetic disorder and a larger exciton diffusion coefficient. GS-ISO also possesses a higher electroluminescence external quantum efficiency of 1.0×10-2 . The organic photovoltaic cell based on PBDB-TF:GS-ISO demonstrates a power conversion efficiency of 11.62% under the standard one sun illumination. Besides, the PBDB-TF:GS-ISO-based cell with the effective area of 1.0 cm2 exhibits a power conversion efficiency of 28.37% under the 2700 K illumination of 500 lux. The tandem organic photovoltaic cell using PBDB-TF:GS-ISO as the front sub-cell shows an outstanding efficiency of 19.10%. Importantly, the GS-ISO-based organic photovoltaic cell exhibits promising stability under the continuous illumination of the simulated sunlight. This study indicates that the molecular design strategy demonstrated in this work has great superiority in developing non-fused non-fullerene acceptors and also GS-ISO is a promising wide bandgap acceptor for versatile photovoltaic applications. This article is protected by copyright. All rights reserved.