title: Chemically specific dynamic characterization of photovoltaic and photoconductivity effects of surface nanostructures.
abstract: We report characterization of photovoltaic and photoconductivity effects on nanostructured surfaces through light induced changes in the X-ray photoelectron spectra (XPS). The technique combines the chemical specificity of XPS and the power of surface photovoltage spectroscopy (SPV), with the addition of the ability to characterize photoconductivity under both static and dynamic optical excitation. A theoretical model that quantitatively describes the features of the observed spectra is presented. We demonstrate the applicability of the model on a multitude of sample systems, including homo- and heterojunction solar cells, CdS nanoparticles on metallic or semiconducting substrates, and carbon nanotube films on silicon substrates.
authors.affiliation: UNAM Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara, Turkey. ekiz@bilkent.edu.tr
authors.forename: Okan Oner
authors.initials: OO
authors.lastname: Ekiz
authors.forename: Koray
authors.initials: K
authors.lastname: Mizrak
authors.forename: Aykutlu
authors.initials: A
authors.lastname: Dâna