title: Combined spectroscopic characterization of electron transfer at hybrid CuPcF(16)/GaAs semiconductor interfaces.
abstract: We characterize photoinduced charge injection at the interface between a fluorinated copper phthalocyanine (CuPcF(16)) film deposited over a GaAs(100) wafer by means of pump-probe spectroscopy combined with ultraviolet photoemission spectroscopy (UPS) and electromodulated transmission spectroscopy. UPS characterization of the hybrid interface demonstrates that the CuPcF(16) 's lowest unoccupied molecular level (LUMO) is almost aligned with the GaAs conduction band. Upon photoexcitation of the hybrid interface with 150 fs pulses we observe an efficient photoinduced electron transfer from CuPcF(16) to GaAs. The evolution of interfacial CuPcF(16) charges appear to be strongly influenced by energy level alignment at the GaAs/CuPcF(16) heterojunction.
authors.affiliation: IFN-CNR, Dipartimento di Fisica, ULTRAS-INFM, Politecnico di Milano, Milano 20133, Italy.
authors.forename: Juan
authors.initials: J
authors.lastname: Cabanillas-Gonzalez
authors.forename: Hans-Joachim
authors.initials: HJ
authors.lastname: Egelhaaf
authors.forename: Alberto
authors.initials: A
authors.lastname: Brambilla
authors.forename: Paolo
authors.initials: P
authors.lastname: Sessi
authors.forename: Lamberto
authors.initials: L
authors.lastname: Duò
authors.forename: Marco
authors.initials: M
authors.lastname: Finazzi
authors.forename: Franco
authors.initials: F
authors.lastname: Ciccacci
authors.forename: Guglielmo
authors.initials: G
authors.lastname: Lanzani