Characterization of the Schottky barrier in SrRuO_3/Nb:SrTiO_3 junctions

摘要

Internal photoemission spectroscopy was used to determine the Schottky barrier height in rectifying SrRuO_3/Nb-doped SrTiO_3 junctions for 0.01 and 0.5 wt % Nb concentrations. Good agreement was obtained with the barrier height deduced from capacitance-voltage measurements, provided that a model of the nonlinear permittivity of SrTiO_3 was incorporated in extrapolating the built-in potential, particularly for high Nb concentrations. Given the generic polarizability of perovskites under internal/external electric fields, internal photoemission provides a valuable independent probe of the interface electronic structure.