Solution-Processed Transparent Conducting Electrodes for Flexible Organic Solar Cells with 16.61% Efficiency

• Main Authors: Juanyong Wan, Yonggao Xia, Junfeng Fang, Zhiguo Zhang, Bingang Xu, Jinzhao Wang, Ling Ai, Weijie Song, Kwun Nam Hui, Xi Fan, Yongfang Li
• Format: Article
• Language: English
• Published: SpringerOpen 2021-01-01
• Series: Nano-Micro Letters
• Subjects: Solution-processed transparent conducting electrode; Flexible organic solar cell; PEDOT:PSS; Trifluoromethanesulfonic acid doping; Solution processing
• Online Access: https://doi.org/10.1007/s40820-020-00566-3
• ISSN: 2311-6706; 2150-5551

Abstract Nonfullerene organic solar cells (OSCs) have achieved breakthrough with pushing the efficiency exceeding 17%. While this shed light on OSC commercialization, high-performance flexible OSCs should be pursued through solution manufacturing. Herein, we report a solution-processed flexible OSC based on a transparent conducting PEDOT:PSS anode doped with trifluoromethanesulfonic acid (CF3SO3H). Through a low-concentration and low-temperature CF3SO3H doping, the conducting polymer anodes exhibited a main sheet resistance of 35 Ω sq−1 (minimum value: 32 Ω sq−1), a raised work function (≈ 5.0 eV), a superior wettability, and a high electrical stability. The high work function minimized the energy level mismatch among the anodes, hole-transporting layers and electron-donors of the active layers, thereby leading to an enhanced carrier extraction. The solution-processed flexible OSCs yielded a record-high efficiency of 16.41% (maximum value: 16.61%). Besides, the flexible OSCs afforded the 1000 cyclic bending tests at the radius of 1.5 mm and the long-time thermal treatments at 85 °C, demonstrating a high flexibility and a good thermal stability.