Delicate chemical structure regulation of nonfullerene acceptor for efficient and large thickness organic solar cells
By
Zhang, Z (Zhang, Zhe) [1] , [2] , [3] ; Feng, WY (Feng, Wanying) [1] , [2] , [3] ; Zhang, YX (Zhang, Yunxin) [4] ; Yuan, SH (Yuan, Shaohui) [4] ; Bai, YY (Bai, Yuyang) [4] ; Wang, PR (Wang, Peiran) [1] , [2] , [3] ; Yao, ZY (Yao, Zhaoyang) [1] , [2] , [3] ; Li, CX (Li, Chenxi) [1] , [2] , [3] ; Duan, TN (Duan, Tainan) [5] ; Wan, XJ (Wan, Xiangjian) [1] , [2] , [3] ; Kan, B (Kan, Bin) [4] ; Chen, YS (Chen, Yongsheng) [1] , [2] , [3]
Early Access
APR 2024
Indexed
2024-05-01
Document Type
Article; Early Access
Abstract
Inspired by the success of CH-series acceptors, a small-molecular acceptor, CH-Tz was reported by adopting a new conjugation-extended electron-deficient unit ([1,2,5]thiadiazolo[3,4-b]pyrazine) on the central core. Owing to the enhanced inter-/intra-molecular interactions, CH-Tz exhibited near-infrared absorption and an effective three-dimensional molecular packing network in its single crystal. When blended with polymer donor PM6, the binary device achieved a high power conversion efficiency (PCE) of 18.54%, with a notable short-circuit current density (Jsc) of 27.54 mA cm-2 and an excellent fill factor (FF) over 80%, which can be partly ascribed to the balanced charge transport properties in the blend film. After employing D18-Cl as the third component, an enhanced PCE of 18.85% was achieved due to a more obvious fiber network. Impressively, the CH-Tz-based OSC devices show excellent thermal stability and thickness insensitivity. Record-breaking Jsc of 28.92 mA cm-2 was reached for PM6:D18-Cl:CH-Tz ternary device with a thickness of 560 nm. Besides, CH-Tz shows potential in fabricating multicomponent high-performance organic solar cells, where over 19% efficiency could be realized in the quaternary device. Our work advances the strong influence of electron-deficient central units on molecular photovoltaic properties and guides the design of acceptors for stable and large-thickness organic solar cells.