title: Photoprecursor approach as an effective means for preparing multilayer organic semiconducting thin films by solution processes.
abstract: The vertical composition profile of active layer has a major effect on the performance of organic photovoltaic devices (OPVs). While stepwise deposition of different materials is a conceptually straightforward method for controlled preparation of multi-component active layers, it is practically challenging for solution processes because of dissolution of the lower layer. Herein, we overcome this difficulty by employing the photoprecursor approach, in which a soluble photoprecursor is solution-deposited then photoconverted in situ to a poorly soluble organic semiconductor. This approach enables solution-processing of the p-i-n triple-layer architecture that has been suggested to be effective in obtaining efficient OPVs. We show that, when 2,6-dithienylanthracene and a fullerene derivative PC71BM are used as donor and acceptor, respectively, the best p-i-n OPV affords a higher photovoltaic efficiency than the corresponding p-n device by 24% and bulk-heterojunction device by 67%. The photoprecursor approach is also applied to preparation of three-component p-i-n films containing another donor 2,6-bis(5'-(2-ethylhexyl)-(2,2'-bithiophen)-5-yl)anthracene in the i-layer to provide a nearly doubled efficiency as compared to the original two-component p-i-n system. These results indicate that the present approach can serve as an effective means for controlled preparation of well-performing multi-component active layers in OPVs and related organic electronic devices.
authors.affiliation: Department of Organic Device Engineering, Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata 992-8510, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Yamaguchi
authors.affiliation: Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, Nara 630-0192, Japan.
authors.forename: Mitsuharu
authors.initials: M
authors.lastname: Suzuki
authors.affiliation: Department of Organic Device Engineering, Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata 992-8510, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Motoyama
authors.affiliation: Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, Nara 630-0192, Japan.
authors.forename: Shuhei
authors.initials: S
authors.lastname: Sugii
authors.affiliation: Department of Organic Device Engineering, Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata 992-8510, Japan.
authors.forename: Chiho
authors.initials: C
authors.lastname: Katagiri
authors.affiliation: Department of Polymer Science and Engineering, Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata 992-8510, Japan.
authors.forename: Katsuya
authors.initials: K
authors.lastname: Takahira
authors.affiliation: Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, Nara 630-0192, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Ikeda
authors.affiliation: 1] Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, Nara 630-0192, Japan [2] CREST, JST, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Yamada
authors.affiliation: 1] Department of Organic Device Engineering, Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata 992-8510, Japan [2] CREST, JST, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan.
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Nakayama