Dominant effects of first monolayer energetics at donor/acceptor interfaces on organic photovoltaics

Seiichiro Izawa; Kyohei Nakano; Kaori Suzuki; Kazuhito Hashimoto; Keisuke Tajima

doi:10.1002/adma.201500840

Dominant effects of first monolayer energetics at donor/acceptor interfaces on organic photovoltaics

Adv Mater. 2015 May 20;27(19):3025-31. doi: 10.1002/adma.201500840. Epub 2015 Apr 9.

Authors

Seiichiro Izawa^{1

2}, Kyohei Nakano¹, Kaori Suzuki¹, Kazuhito Hashimoto², Keisuke Tajima^{1

3}

Affiliations

¹ RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.
² Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
³ Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan.

PMID: 25856403
DOI: 10.1002/adma.201500840

Abstract

Energy levels of the first monolayer are manipulated at donor/acceptor interfaces in planar heterojunction organic photovoltaics by using molecular self-organization. A "cascade" energy landscape allows thermal-activation-free charge generation by photoirradiation, destabilizes the energy of the interfacial charge-transfer state, and suppresses bimolecular charge recombination, resulting in a higher open-circuit voltage and fill factor.

Keywords: cascade energy landscape; charge recombination; charge separation; donor/acceptor interfaces; organic photovoltaics.