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

• Published in: Nano-micro letters Vol. 13; no. 1; pp. 44 - 14
• Main Authors: Wan, Juanyong, Xia, Yonggao, Fang, Junfeng, Zhang, Zhiguo, Xu, Bingang, Wang, Jinzhao, Ai, Ling, Song, Weijie, Hui, Kwun Nam, Fan, Xi, Li, Yongfang
• Format: Journal Article
• Language: English
• Published: Singapore Springer Nature Singapore 01.12.2021; Springer Nature B.V; SpringerOpen
• Subjects: Anodes; Commercialization; Conducting polymers; Efficiency; Electrodes; Energy levels; Engineering; Flexibility; Flexible organic solar cell; Low temperature; Nanoscale Science and Technology; Nanotechnology; Nanotechnology and Microengineering; Organic Solar Cells; PEDOT:PSS; Photovoltaic cells; Solar cells; Solution processing; Solution-processed transparent conducting electrode; Thermal stability; Triflic acid; Trifluoromethanesulfonic acid doping; Wettability; Work functions; Trifluoromethanesulfonic acid doping; Solution-processed transparent conducting electrode; Solution processing; Flexible organic solar cell; PEDOT:PSS
• ISSN: 2311-6706; 2150-5551; 2150-5551
• DOI: 10.1007/s40820-020-00566-3

Highlights The PEDOT:PSS flexible electrodes with a unique CF 3 SO 3 H treatment exhibited high electrical characteristics and stability. An energy level tuning effect was induced to create a suitable work function. Flexible organic solar cells yielded a record-high efficiency of 16.61%, a high flexibility, and a good thermal stability. 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 (CF 3 SO 3 H). Through a low-concentration and low-temperature CF 3 SO 3 H 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.