有机太阳能电池
材料科学
烷基
小分子
电致发光
退火(玻璃)
接受者
分子
光电子学
富勒烯
化学物理
光化学
分析化学(期刊)
纳米技术
聚合物
化学
有机化学
凝聚态物理
复合材料
物理
图层(电子)
生物化学
作者
Lili Zhang,Rui Sun,Ziqi Zhang,Jianqi Zhang,Qinglian Zhu,Wei Ma,Jie Min,Zhixiang Wei,Dan Deng
标识
DOI:10.1002/adma.202207020
摘要
Abstract A critical bottleneck for further efficiency breakthroughs in organic solar cells (OSCs) is to minimize the non‐radiative energy loss ( e Δ V nr ) while maximizing the charge generation. With the development of highly emissive low‐bandgap non‐fullerene acceptors, the design of high‐performance donors becomes critical to enable the blend with the electroluminescence quantum efficiency to approach or surpass the pristine acceptor. Herein, by shortening the end‐capped alkyl chains of the small‐molecular donors from hexyl (MPhS‐C6) to ethyl (MPhS‐C2), the material obtained aggregation that was insensitive to thermal annealing (TA) along with condensed packing simultaneously. The former leads to small phase separation and suppressed upshifts of the highest occupied molecular orbital energy level during TA, and the latter facilitates its efficient charge‐transport at aggregation‐less packing. Hence, the Δ V nr decreases from 0.242 to 0.182 V, from MPhS‐C6 to MPhS‐C2 based OSCs. An excellent PCE of 17.11% is obtained by 1,8‐diiodoctane addition due to almost unchanged high J sc (26.6 mA cm −2 ) and V oc (0.888 V) with improved fill factor, which is the record efficiency with the smallest energy loss (0.497 eV) and Δ V nr (0.192 V) in all‐small‐molecule OSCs. These results emphasize the potential material design direction of obtaining concurrent TA‐insensitive aggregation and condensed packing to maximize the device performances with a super low Δ V nr .
科研通智能强力驱动
Strongly Powered by AbleSci AI