Zhi Jiang, Kenjiro Fukuda, Wenchao Huang, Sungjun Park, Roda Nur, Md Osman Goni Nayeem, Kilho Yu, Daishi Inoue, Masahiko Saito, Hiroki Kimura, Tomoyuki Yokota, Shinjiro Umezu, Daisuke Hashizume, Itaru Osaka, Kazuo Takimiya, Takao Someya, “Durable Ultraflexible Organic Photovoltaics with Novel Metal‐Oxide‐Free Cathode”, Advanced Functional Materials, Volume 29, Issue 5, DOI:10.1002/adfm.2018083782018.12.19