Block copolymers as efficient cathode interlayer materials for organic solar cells

Abstract

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.

Graphical abstract

Keywords

organic solar cell / block copolymer / cathode interlayer

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Acknowledgments

This work was financially supported by research grants from the National Natural Science Foundation of China (Grant Nos. 21801238 and 61504015), National Youth Thousand Program Project (Grant No. R52A199Z11), CAS Pioneer Hundred Talents Program B (Grant No. Y92A010Q10), National Special Funds for Repairing and Purchasing Scientific Institutions (Grant No. Y72Z090Q10), the Natural Science Foundation of Chongqing (Grant Nos. cstc2017jcyjA0752, cstc2018jcyjAX0556, cstc2017jcy-jAX0384, and cstc2018jszx-cyzdX0137), the “artificial intelligence” key project of Chongqing (Grant No. cstc2017rgzn-zdyfX0030), the Key Laboratory of Low-grade Energy Utilization Technologies and Systems (Grant Nos. LLEUTS-2017004, LLEUTS-2019001), the Venture & Innovation Support Program for Chongqing Overseas Returnees (Grant Nos. cx2017034 and cx2019028), Chongqing Talents Top Youth Talent Program (Grant No. CQYC201905057).

Electronic Supplementary Material

Supplementary material is available in the online version of this article at https://doi.org/10.1007/s11705-020-2010-1 and is accessible for authorized users.

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