EXPLORATION OF NOVEL ULTRAWIDE-BAND-GAP HETEROVALENT TERNARY OXIDE LIGAO2 FOR EXTREME ENVIRONMENT
Abstract
An experimental crystal growth and characterization effort is proposed to develop LiGaO2 as an ultrawide-band-gap (UWBG) heterovalent ternary oxide semiconductor. Given the high degree of ionicity of the bonding, it prefers the hexagonal wurtzite related structure. This provides additional flexibility in designing desirable band structure and device relevant properties and integration with more traditional semiconductors such as GaN, ZnO. In LiGaO2, the next higher conduction bands above the conduction band minimum occur about 4 eV higher. In addition, the absence of subsidiary valleys or local minima in k-space can avoid materials breakdown through intervalley scattering under high field operation. These fundamental properties promise LiGaO2 as a novel material platform for future device technologies, particularly for extreme environment applications. An important unsolved problem with most oxides is that p-type doping seems unfeasible, which is due to the localized nature of O-2p orbitals and a high electronegativity of oxygen lead to a large hole mass and difficulty in introducing shallow acceptors. The design strategy for p-type UWBG oxide semiconductor would critically relying on reducing the localization behavior of valence band (VB). The concept of chemical modulation of the valence band by modifying the VB through the hybridization of oxygen 2p orbitals with metal d or s orbital can be a promising route toward p-type. The development of heterovalent ternary oxide such as LiGaO2 allows the flexibility
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 29, 2024
- Source ID
- FA95502310142
Entities
People
- Hongping Zhao
Organizations
- Air Force Office of Scientific Research
- Ohio State University
- United States Air Force