Potential Profiling of the Nanometer-Scale Charge Depletion Layer in n-ZnO/p-NiO Junction Using Photoemission Spectroscopy

TL;DR

This study uses photoemission spectroscopy to analyze the charge depletion layer in an all-oxide n-ZnO/p-NiO p-n junction, revealing detailed potential profiles and depletion widths at the nanometer scale.

Contribution

It introduces a method combining photoemission spectroscopy and Ar-ion sputtering to profile the charge depletion layer in oxide p-n junctions at nanometer resolution.

Findings

Charge depletion width of 2.3 nm on ZnO side

Built-in potential of 0.54 eV

Depth-profile analysis of oxide p-n junctions

Abstract

We have performed a depth-profile analysis of an all-oxide p-n junction diode n-ZnO/p-NiO using photoemission spectroscopy combined with Ar-ion sputtering. Systematic core-level shifts were observed during the gradual removal of the ZnO overlayer, and were interpreted using a simple model based on charge conservation. Spatial profile of the potential around the interface was deduced, including the charge-depletion width of 2.3 nm extending on the ZnO side and the built-in potential of 0.54 eV.