Suppressing non-radiative recombination and tuning morphology via central core asymmetric substitution for efficient organic solar cells
By
Si, XD (Si, Xiaodong) [1] , [2] ; Shi, WD (Shi, Wendi) [1] , [2] ; Wang, RH (Wang, Ruohan) [1] , [2] ; Zhao, WK (Zhao, Wenkai) [3] ; Suo, ZC (Suo, Zhaochen) [1] , [2] ; Fu, Z (Fu, Zhen) [4] ; Long, GK (Long, Guankui) [3] ; Hao, XT (Hao, Xiaotao) [4] ; Yao, ZY (Yao, Zhaoyang) [1] , [2] ; Wan, XJ (Wan, Xiangjian) [1] , [2] ; Li, CX (Li, Chenxi) [1] , [2] ; Chen, YS (Chen, Yongsheng) [1] , [2]
Volume
131Part
A
DOI
10.1016/j.nanoen.2024.110204
Article Number
110204
Published
DEC 1 2024
Indexed
2024-09-19
Document Type
Article
Jump to
Abstract
It is necessary and challenging to achieve high-efficiency organic solar cells (OSCs) by suppressing nonradiative energy loss (Delta E-nr) and fine-tuning active layer morphology through the delicate active material design. In this study, we design two asymmetric acceptors, a-CH-ThCl and a-CH-Th2Cl, featuring asymmetric conjugated substitutions on central cores via single bond linkages. Single crystals analysis indicate that these two acceptors exhibit intense J-aggregation induced by the asymmetric substitution, which favours for their high photoluminescence quantum yields and contributes to reducing non-radiative recombination. Meanwhile, the two asymmetric acceptors demonstrate enhanced miscibility and optimized morphology with the donor D18. Consequently, the binary device based on D18: a-CH-Th2Cl demonstrates an impressive efficiency of up to 19.10 % with a high open-circuit voltage of 0.935 V, attributed to the remarkably low Delta E-nr of 0.179 eV and optimized morphology. These results provide an effective strategy for material design to optimize molecular packing, reduce non-radiative recombination and tune active layer morphology to achieve high-efficiency OSCs.