title: Long-term efficient organic photovoltaics based on quaternary bulk heterojunctions.
abstract: A major impediment to the commercialization of organic photovoltaics (OPVs) is attaining long-term morphological stability of the bulk heterojunction (BHJ) layer. To secure the stability while pursuing optimized performance, multi-component BHJ-based OPVs have been strategically explored. Here we demonstrate the use of quaternary BHJs (q-BHJs) composed of two conjugated polymer donors and two fullerene acceptors as a novel platform to produce high-efficiency and long-term durable OPVs. A q-BHJ OPV (q-OPV) with an experimentally optimized composition exhibits an enhanced efficiency and extended operational lifetime than does the binary reference OPV. The q-OPV would retain more than 72% of its initial efficiency (for example, 8.42-6.06%) after a 1-year operation at an elevated temperature of 65 °C. This is superior to those of the state-of-the-art BHJ-based OPVs. We attribute the enhanced stability to the significant suppression of domain growth and phase separation between the components via kinetic trapping effect.
authors.affiliation: Department of Applied Chemistry, Kyung Hee University, Yongin, Gyeonggi 17104, Republic of Korea.
authors.forename: Minwoo
authors.initials: M
authors.lastname: Nam
authors.affiliation: Department of Applied Chemistry, Kyung Hee University, Yongin, Gyeonggi 17104, Republic of Korea.
authors.forename: Minjeong
authors.initials: M
authors.lastname: Cha
authors.affiliation: Pohang Accelerator Laboratory, Pohang, Gyeongbuk 37673, Republic of Korea.
authors.forename: Hyun Hwi
authors.initials: HH
authors.lastname: Lee
authors.affiliation: Computational Science Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea.
authors.forename: Kahyun
authors.initials: K
authors.lastname: Hur
authors.affiliation: Department of Applied Chemistry, Kyung Hee University, Yongin, Gyeonggi 17104, Republic of Korea.
authors.forename: Kyu-Tae
authors.initials: KT
authors.lastname: Lee
authors.affiliation: Department of Applied Chemistry, Kyung Hee University, Yongin, Gyeonggi 17104, Republic of Korea.
authors.forename: Jaehong
authors.initials: J
authors.lastname: Yoo
authors.affiliation: Nanophotonics Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea.
authors.forename: Il Ki
authors.initials: IK
authors.lastname: Han
authors.affiliation: Nanophotonics Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea.
authors.forename: S Joon
authors.initials: SJ
authors.lastname: Kwon
authors.affiliation: Department of Applied Chemistry, Kyung Hee University, Yongin, Gyeonggi 17104, Republic of Korea.
authors.forename: Doo-Hyun
authors.initials: DH
authors.lastname: Ko