Characterization of the Schottky Barrier in SrRuO3/Nb:SrTiO3 Junctions

TL;DR

This study uses internal photoemission spectroscopy to accurately measure the Schottky barrier height in SrRuO3/Nb:SrTiO3 junctions, highlighting the importance of considering nonlinear permittivity effects for precise characterization.

Contribution

It demonstrates the effectiveness of internal photoemission spectroscopy as an independent method for probing interface electronic structures in complex oxide junctions, accounting for nonlinear dielectric behavior.

Findings

Good agreement between photoemission and capacitance-voltage measurements when nonlinear permittivity is included.

Nonlinear permittivity modeling is crucial for accurate barrier height determination at high Nb concentrations.

Internal photoemission is a valuable tool for studying interface electronic properties in polarizable perovskite materials.

Abstract

Internal photoemission spectroscopy was used to determine the Schottky barrier height in rectifying SrRuO3/Nb-doped SrTiO3 junctions for 0.01 wt % 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 SrTiO3 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.