1. Chongqing Institute of Green and Intelligent Technology, Chongqing School, University of Chinese Academy of Sciences (UCAS Chongqing), Chinese Academy of Sciences, Chongqing 400714, China 2. MOE Key Laboratory of Low-Grade Energy Utilization Technologies and Systems, School of Energy & Power Engineering, Chongqing University, Chongqing 400044, China 3. Library & Information Center, Anhui University of Finance and Economics, Bengbu 233030, China
Emerging needs for the large-scale industrialization of organic solar cells require high performance cathode interlayers to facilitate the charge extraction from organic semiconductors. In addition to improving the efficiency, stability and processability issues are major challenges. Herein, we design block copolymers with well controlled chemical composition and molecular weight for cathode interlayer applications. The block copolymer coated cathodes display high optical transmittance and low work function. Conductivity studies reveal that the block copolymer thin film has abundant conductive channels and excellent longitudinal electron conductivity due to the interpenetrating networks formed by the polymer blocks. Applications of the cathode interlayers in organic solar cells provide higher power conversion efficiency and better stability compared to the most widely-applied ZnO counterparts. Furthermore, no post-treatment is needed which enables excellent processability of the block copolymer based cathode interlayer.
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