Engineering Ga2O3 phases with MIST-CVD for Gas Sensing Applications

Abstract

With the utilization of UV-C radiation sterilizers on the ascension in the wake of the recent pandemic, it has become imperative to have health safety systems in place to curb the ill effects on humans. This requires detection systems with felicitous spectral replication to the “invisible to the unclad eye” radiation leaks with utmost sensitivity and swiftness. Gallium Oxide (Ga2O3), a semiconductor, has gained a lot of attention among researchers due to its ultra-wideband gap (4.9eV) and high critical field with a value of 8 MV/cm. It is Transparent Conductive Oxide (TCO). Ga2O3 has five different atomic structures of Ga2O3, namely, the monoclinic (β-Ga2O3), rhombohedral (α), defective spinel (γ), cubic (δ), and orthorhombic (ε) structures. Of these, the β-polymorph is selected because of band gap energy (Eg ≈ 4.7–4.9 eV), it is highly stable in thermal and chemical properties. In this context, the present article demonstrates the best and most suitable technique for the deposition of β-Ga2O3 (Gallium Oxide). This work demonstrates the layer deposition of β-Ga2O3 (Gallium Oxide) thin-film with MIST-CVD (Chemical Vapor Deposition) and optimization of the deposited layer to the extent of using different techniques and analyzing different plots. This deposited layer on a substrate is used for applications of gas sensors or Ultraviolet-Photodetectors (UV-PDs. This article has also demonstrated the successful application of optimized thin film for gas sensing.