Tandem organic solar cells with 20.6% efficiency enabled by reduced voltage losses

Jianqiu Wang; Zhong Zheng; Pengqing Bi; Zhihao Chen; Yafei Wang; Xiaoyu Liu; Shaoqing Zhang; Xiaotao Hao; Maojie Zhang; Yongfang Li; Jianhui Hou

doi:10.1093/nsr/nwad085

Tandem organic solar cells with 20.6% efficiency enabled by reduced voltage losses

Natl Sci Rev. 2023 Mar 30;10(6):nwad085. doi: 10.1093/nsr/nwad085. eCollection 2023 Jun.

Authors

Jianqiu Wang^{1

2}, Zhong Zheng^{1

3}, Pengqing Bi¹, Zhihao Chen^{1

4}, Yafei Wang^{1

5}, Xiaoyu Liu^{1

3}, Shaoqing Zhang^{1

3}, Xiaotao Hao⁴, Maojie Zhang², Yongfang Li^{2

6

5}, Jianhui Hou^{1

3

5}

Affiliations

¹ State Key Laboratory of Polymer Physics and Chemistry, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
² Laboratory of Advanced Optoelectronic Materials, Suzhou Key Laboratory of Novel Semiconductor-optoelectronics Materials and Devices, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China.
³ School of Chemistry and Biology Engineering, University of Science and Technology Beijing, Beijing 100083, China.
⁴ School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
⁵ University of Chinese Academy of Sciences, Beijing 100049, China.
⁶ CAS Key Laboratory of Organic Solids, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.

Abstract

Large voltage losses are the main obstacle for achieving high efficiency in organic solar cells (OSCs). Here we construct ternary OSCs by introducing an asymmetric small molecule acceptor AITC into PBDB-TCl : BTP-eC9 system and demonstrate the effectiveness in simultaneously decreasing energy disorder and non-radiative voltage losses. It is found that the introduction of AITC can modify domain size and increase the degree of crystallinity, which enhances open-circuit voltage and power conversion efficiency (19.1%, certified as 18.9%). Inspiringly, an output efficiency of 20.6% of the constructed tandem OSCs based on PBDB-TCl : AITC : BTP-eC9 ternary active layer output a recorded efficiency of 20.6% (certified as 20.3%), which is the highest value in OSCs field to date. This work demonstrates that decreasing the voltage losses by ternary strategy and constructing of tandem architecture are effective approaches towards improving photovoltaic performance.

Keywords: organic solar cells; power conversion efficiency; tandem cells; ternary strategy; voltage losses.