Conduction and valence band offsets of Ga2O3/h-BN heterojunction

TL;DR

This study characterizes the band offsets of the Ga2O3/h-BN heterojunction, revealing a type-II alignment with large offsets that could enhance electron confinement in devices.

Contribution

It provides the first detailed measurement of valence and conduction band offsets for Ga2O3/h-BN heterojunctions using advanced spectroscopy techniques.

Findings

Valence band offset of 1.75 eV

Conduction band offset of 3.35-3.65 eV

Type-II heterojunction with potential for electron confinement

Abstract

h-BN and Ga2O3 are two promising semiconductor materials. However, the band alignment of the Ga2O3/h-BN heterojunction has not been identified, hindering device development. In this study, the heterojunction was prepared by metalorganic chemical vapor deposition and pulsed laser deposition. Transmission electron microscopy confirmed sharp heterointerface and revealed structural evolution as amorphous-Ga2O3 grew thicker on lattice mismatched h-BN. The valence and conduction band offsets were determined by high-resolution X-ray photoemission spectroscopy to be 1.75 and 3.35-3.65 eV, respectively, corresponding to a type-II heterojunction. The extremely large type-II band offsets along with indirect bandgap of Ga2O3 may be leveraged for exceptional electron confinement and storage.