title: Competition between charge-transfer exciton dissociation and direct photocarrier generation in molecular donor-acceptor compounds.
abstract: The interfacial charge-separation and photovoltaic characteristics of a molecular donor-acceptor charge-transfer compound were examined. Measurements of laser beam-induced currents on the single crystals allowed selective detection of hole and electron photocurrents through the metal-semiconductor interfaces. This method also reveals the exceptionally long diffusion length of 20  μm in the crystal. The transition from charge-transfer exciton dissociation to direct photocarrier generation is discussed on the basis of the photon-energy-dependent diffusion length and photon-to-current conversion spectrum.
authors.affiliation: Photonics Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan.
authors.forename: Jun'ya
authors.initials: J
authors.lastname: Tsutsumi
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Yamada
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Matsui
authors.forename: Simon
authors.initials: S
authors.lastname: Haas
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Hasegawa