Nature of the band gap of In2O3 revealed by first-principles calculations and x-ray spectroscopy
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Updated: Jul 4, 2026

Probe Type II Band Alignment in One-Dimensional Van Der Waals Heterostructures Using First-Principles Calculations
Published on: October 12, 2019
Aron Walsh1, Juarez L F Da Silva, Su-Huai Wei
1National Renewable Energy Laboratory, Golden, Colorado 80401, USA. aron_walsh@nrel.gov
Abstract:
Bulk and surface sensitive x-ray spectroscopic techniques are applied in tandem to show that the valence band edge for In2O3 is found significantly closer to the bottom of the conduction band than expected on the basis of the widely quoted bulk band gap of 3.75 eV. First-principles theory shows that the upper valence bands of In2O3 exhibit a small dispersion and the conduction band minimum is positioned at Gamma. However, direct optical transitions give a minimal dipole intensity until 0.8 eV below the valence band maximum. The results set an upper limit on the fundamental band gap of 2.9 eV.
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