1. Highly efficient organic solar cells enabled by suppressing triplet exciton formation and non-radiative recombination
- Author
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Congqi Li, Guo Yao, Xiaobin Gu, Jikai Lv, Yuqi Hou, Qijie Lin, Na Yu, Misbah Sehar Abbasi, Xin Zhang, Jianqi Zhang, Zheng Tang, Qian Peng, Chunfeng Zhang, Yunhao Cai, and Hui Huang
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Science - Abstract
Abstract The high non-radiative energy loss is a bottleneck issue that impedes the improvement of organic solar cells. The formation of triplet exciton is thought to be the main source of the large non-radiative energy loss. Decreasing the rate of back charge transfer is considered as an effective approach to alleviate the relaxation of the charge-transfer state and the triplet exciton generation. Herein, we develops an efficient ternary system based on D18:N3-BO:F-BTA3 by regulating the charge-transfer state disorder and the rate of back charge transfer of the blend. With the addition of F-BTA3, a well-defined morphology with a more condensed molecular packing is obtained. Moreover, a reduced charge-transfer state disorder is demonstrated in the ternary blend, which decreases the rate of back charge transfer as well as the triplet exciton formation, and therefore hinders the non-radiative recombination pathways. Consequently, D18:N3-BO:F-BTA3-based device produces a low non-radiative energy loss of 0.183 eV and a record-high efficiency of 20.25%. This work not only points towards the significant role of the charge-transfer state disorder on the suppression of triplet exciton formation and the non-radiative energy loss, but also provides a valuable insight for enhancing the performance of OSCs.
- Published
- 2024
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