Impedance spectroscopic studies of the electric conduction in polycrystalline β-Ga2O3

• Published in: Journal of the Electrochemical Society 2000-07, Vol.147 (7), p.2644-2646
• Main Authors: KISS, G, KOVACS, K, PERCZEL, I. V, JOSEPOVITS, V. K, FLEISCHER, M, MEIXNER, H, RETI, F
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electrical properties of specific thin films; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Iii-v semiconductors; Physics
• ISSN: 0013-4651; 1945-7111
• DOI: 10.1149/1.1393583

Nonstoichiometric beta-Ga2O3 is a promising base material for high temperature chemical gas sensors. Impedance spectroscopy was used to distinguish the bulk and grain-boundary conduction phenomena in a nonstoichiometric, polycrystalline beta-Ga2O3 thin layer with a grain size of 30 nm, between 567 and 790 C. When oxygen was present, between 567 and 630 C, the width of the depletion layer exceeded the half-diameter of the grains, and the grain was completely depleted. However, as the effective Debye length decreased with increasing temperature above 630 C, the grain was not completely depleted. The conduction mechanism in the bulk was the same in the whole temperature range studied. The activation energy was determined to be 1.2 eV. 17 refs.