Insulator-donor electron wavefunction coupling in pseudo-bilayer organic solar cells achieving a certificated efficiency of 19.18

Jiangkai Sun; Ruijie Ma; Xue Yang; Xiaoyu Xie; Dongcheng Jiang; Yuan Meng; Yiyun Li; Fengzhe Cui; Mengfei Xiao; Kangning Zhang; Yu Chen; Xinxin Xia; Maojie Zhang; Xiaoyan Du; Long Ye; Haibo Ma; Kun Gao; Feng Chen; Gang Li; Xiaotao Hao; Hang Yin

doi:10.1093/nsr/nwae385

Insulator-donor electron wavefunction coupling in pseudo-bilayer organic solar cells achieving a certificated efficiency of 19.18

Natl Sci Rev. 2024 Oct 30;12(1):nwae385. doi: 10.1093/nsr/nwae385. eCollection 2025 Jan.

Authors

Jiangkai Sun¹, Ruijie Ma², Xue Yang¹, Xiaoyu Xie³, Dongcheng Jiang¹, Yuan Meng¹, Yiyun Li¹, Fengzhe Cui¹, Mengfei Xiao¹, Kangning Zhang¹, Yu Chen⁴, Xinxin Xia⁵, Maojie Zhang⁵, Xiaoyan Du¹, Long Ye⁶, Haibo Ma³, Kun Gao¹, Feng Chen¹, Gang Li², Xiaotao Hao¹, Hang Yin¹

Affiliations

¹ School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
² Department of Electric and Electronic Engineering, Research Institute for Smart Energy (RISE), Photonic Research Institute (PRI), The Hong Kong Polytechnic University, Hong Kong 999077, China.
³ Qingdao Institute for Theoretical and Computational Sciences, School of Chemistry and Chemical Engineering, Shandong University, Qingdao 266237, China.
⁴ Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China.
⁵ National Engineering Research Center for Colloidal Materials, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China.
⁶ School of Materials Science and Engineering, Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin 300350, China.

Abstract

The incorporation of polymeric insulators has led to notable achievements in the field of organic semiconductors. By altering the blending concentration, polymeric insulators exhibit extensive capabilities in regulating molecular configuration, film crystallinity, and mitigation of defect states. However, current research suggests that the improvement in such physical properties is primarily attributed to the enhancement of thin film morphology, an outcome that seems to be an inevitable consequence of incorporating insulators. Herein, we report a general and completely new effect of polymeric insulators in organic semiconductors: the insulator-donor electron wavefunction coupling effect. Such insulators can couple with donor polymers to reduce the energy barrier level and facilitate intramolecular electron transport. Besides the morphological effects, we observed that this coupling effect is another mechanism that can significantly enhance electron mobility (up to 100 times) through the incorporation of polymeric insulators in a series of donor systems. With this effect, we proposed a polymeric insulator blending approach to fabricate state-of-the-art pseudo-bilayer organic solar cells, and the PM6/L8-BO device exhibits a high efficiency of 19.50% (certificated 19.18%) with an improved interfacial electron transport property. This work not only offers a novel perspective on the quantum effect of polymeric insulators in organic semiconductors, but also presents a simple yet effective method for enhancing the performance of organic solar cells.

Keywords: electron transport; organic semiconductors; organic solar cells; polymeric insulators.