Regensburg 2010 – scientific programme

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DF: Fachverband Dielektrische Festkörper

DF 10: Dielectric surfaces and interfaces

DF 10.4: Talk

Wednesday, March 24, 2010, 15:25–15:45, H11

An electronic defect state analysis in perovskite heterostructures by surface photovoltage spectroscopy — •Jana Becherer, Elke Beyreuther, Stefan Grafström, and Lukas M. Eng — Institut für Angewandte Photophysik, Technische Universität Dresden, D-01062 Dresden

Surface photovoltage (SPV) spectroscopy provides a nondestructive, contact-free method to characterize and quantify electronic trap states within the bandgap of a semiconducting material. In the present study we apply the method to determine electronic defect states of wide-bandgap perovskite oxides.

For different perovskites (SrTiO₃ and BaTiO₃ single crystals, lead zirconate titanate and lanthanum manganite thin films on SrTiO₃ substrates) wavelength-, intensity-, temperature-, and time-resolved surface photovoltage spectroscopy was performed using a Kelvin probe setup in air. Analysis of these measurements provides surface, interface, and bulk state properties, i.e., their energy position and distribution, density, and transition probabilities such as the thermal and optical cross sections. We discuss the results and their impacts in detail.