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DF: Fachverband Dielektrische Festkörper

DF 16: Dielectric surfaces and interfaces

DF 16.4: Talk

Thursday, March 17, 2011, 15:15–15:35, MÜL Elch

Investigating electronic defects in strontium titanate by surface photovoltage analysis — •Elke Beyreuther, Jana Becherer, Stefan Grafström, and Lukas M. Eng — Institut für Angewandte Photophysik, Technische Universität Dresden, D-01062 Dresden, Germany

The energy distribution of electronic defect states within the bandgap of oxygen-reduced n-type strontium titanate has been analyzed by means of wavelength-dependent surface photovoltage (SPV) measurements using a Kelvin probe set-up. As a further result, the parameters of several surface states, i.e. the trap state density and the thermal and optical cross sections, were extracted from SPV transients.

Finally, the appropriateness of the method as a general tool for electrical characterization of complex oxide surfaces is illustrated by applying the SPV technique to comparable oxide crystals such as undoped SrTiO₃, Nb-doped SrTiO₃, or BaTiO₃.