Over 19.2% Efficiency of Organic Solar Cells Enabled by Precisely Tuning the Charge Transfer State Via Donor Alloy Strategy

Jinhua Gao; Na Yu; Zhihao Chen; Yanan Wei; Congqi Li; Tianhua Liu; Xiaobin Gu; Jianqi Zhang; Zhixiang Wei; Zheng Tang; Xiaotao Hao; Fujun Zhang; Xin Zhang; Hui Huang

doi:10.1002/advs.202203606

Over 19.2% Efficiency of Organic Solar Cells Enabled by Precisely Tuning the Charge Transfer State Via Donor Alloy Strategy

Adv Sci (Weinh). 2022 Oct;9(30):e2203606. doi: 10.1002/advs.202203606. Epub 2022 Aug 23.

Authors

Jinhua Gao¹, Na Yu², Zhihao Chen³, Yanan Wei¹, Congqi Li¹, Tianhua Liu¹, Xiaobin Gu¹, Jianqi Zhang⁴, Zhixiang Wei⁴, Zheng Tang², Xiaotao Hao³, Fujun Zhang⁵, Xin Zhang¹, Hui Huang¹

Affiliations

¹ College of Materials Science and Opto-Electronic Technology, Center of Materials Science and Optoelectronics Engineering, CAS Center for Excellence in Topological Quantum Computation, CAS Key Laboratory of Vacuum Physic, University of Chinese Academy of Sciences, Beijing, 100049, China.
² Center for Advanced Low-Dimension Materials, State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai, 201620, China.
³ School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong, 250100, China.
⁴ Center for Excellence in Nanoscience (CAS), Key Laboratory of Nanosystem and Hierarchical Fabrication (CAS), National Center for Nanoscience and Technology, Beijing, 100190, China.
⁵ Key Laboratory of Luminescence and Optical Information, Ministry of Education, Beijing Jiaotong University, Beijing, 100044, China.

Abstract

The large energy loss (E_loss ) is one of the main obstacles to further improve the photovoltaic performance of organic solar cells (OSCs), which is closely related to the charge transfer (CT) state. Herein, ternary donor alloy strategy is used to precisely tune the energy of CT state (E_CT ) and thus the E_loss for boosting the efficiency of OSCs. The elevated E_CT in the ternary OSCs reduce the energy loss for charge generation (ΔE_CT ), and promote the hybridization between localized excitation state and CT state to reduce the nonradiative energy loss (ΔE_nonrad ). Together with the optimal morphology, the ternary OSCs afford an impressive power conversion efficiency of 19.22% with a significantly improved open-circuit voltage (V_oc ) of 0.910 V without sacrificing short-cicuit density (J_sc ) and fill factor (FF) in comparison to the binary ones. This contribution reveals that precisely tuning the E_CT via donor alloy strategy is an efficient way to minimize E_loss and improve the photovoltaic performance of OSCs.

Keywords: charge transfer state; donor alloy strategy; energy loss; organic solar cells.

Abstract

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