title: Photoinduced volume changes in amorphous selenium.
abstract: We have modeled the photoinduced volume change in amorphous selenium. After photon absorption, we treated the excited electron and hole independently within the framework of the tight-binding formalism. We found covalent bond breaking in amorphous networks with photoinduced excited electrons, whereas excited holes contribute to the formation of interchain bonds. We also observed a correlated volume change of the amorphous samples. Our results provide a new and universal description, which can simultaneously explain the photoinduced volume expansion and shrinkage. This model is supported by very recent in situ surface height measurements for amorphous selenium.
authors.affiliation: Department of Physics and Material Sciences Center, Philipps University Marburg, Renthof 5, D-35032 Marburg, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Hegedüs
authors.forename: K
authors.initials: K
authors.lastname: Kohary
authors.forename: D G
authors.initials: DG
authors.lastname: Pettifor
authors.forename: K
authors.initials: K
authors.lastname: Shimakawa
authors.forename: S
authors.initials: S
authors.lastname: Kugler