\beta-Ga2O3-Based Heterojunctions: Exploring Growth Orientations and Alloying Effect

TL;DR

This study examines how alloying and growth orientation influence the electronic properties of eta-Ga2O3 heterojunctions, using first-principles calculations and TCAD modeling to align with experimental data.

Contribution

It provides detailed first-principles calculations of band offsets for various orientations and alloy compositions, highlighting the impact of strain and growth orientation on device modeling.

Findings

Band offsets vary significantly with orientation and alloying.

TCAD models agree with experiments in forward bias.

Growth orientation and strain are crucial for accurate device simulation.

Abstract

We investigate the effects of alloying and growth orientation on the properties of the ultra-wide bandgap semiconductor \beta-Ga2O3 and pseudomorphic AlGaO alloy heterojunctions. Band offsets are computed from first principles using density functional theory (DFT) with the Heyd-Scuseria-Ernzerhof hybrid functional for different Al concentrations and four growth orientations, namely (100)B, (010), (001)B, and ($\bar{2}$01). Significant variations are found and ascribed to the strained pseudomorphic alloys. The values of the band offsets are fed into technology computer-aided design (TCAD) models of Schottky barrier diodes (SBD). I-V and C-V characteristics from the TCAD models show reasonable agreement with recent experimental measurements in the forward bias region. Discrepancies in the negative bias region are expected due to the ideality of the Schottky junctions considered in this study. Our findings underscore the importance of growth orientation and strain in modelling of \beta-Ga2O3-based SBD.