Carbon monoxide gas sensing properties of Ga-doped ZnO film grown by ion plating with DC arc discharge

Abstract

Abstract. The carbon monoxide (CO) gas sensing properties of low-resistance heavily Ga-doped ZnO thin films were evaluated. The ZnO films with a thickness of 50 nm were deposited at 200 • C by ion plating. The electrical properties of the ZnO films were controlled by varying the oxygen assist gas flow rate during deposition. The CO gas sensitivity of ZnO films with Au electrodes was investigated in nitrogen gas at a temperature of 230 to 330 • C. CO gas concentration was varied in the range of 0.6-2.4 % in nitrogen gas. Upon exposure to CO gas, the current flowing through the film was found to decrease. This response occurred even at the lowest temperature of 230 • C, and is thought to be the result of a mechanism different than the previously reported chemical reaction.

Sr- and Ni-doping in ZnO nanorods synthesized by a simple wet chemical method as excellent materials for CO and CO2 gas sensing

“…Besides this the unusual sensing behavior can be ascribed to the chemical reaction of CO molecule by the adsorption to the grain boundary of oxygen gas molecules which plays the key role in physical barrier for carrier's movement and increase the resistance 30 . The inversion of response indicate further that, at low temperature, the pure ZnO and Sr doped sensors behave as p-type semiconductors.…”

Indium-free GZO thin films prepared using plasma-enhanced atomic layer deposition: toward thin film transistor application

“…Recently, pulsed laser deposition, 26,27 molecular beam epitaxy, 28 metal-organic chemical vapor deposition, [29][30][31] chemical spray, [32][33][34] sol-gel methods, [35][36][37] magnetron sputtering, [38][39][40][41][42] arc plasma evaporation, [43][44][45] ion plating [46][47][48] and other methods have been applied for GZO thin film deposition. Owing to the increasing demand for thinner and smaller electronic products, the attention to atomic layer deposition (ALD) technology has also increased as it can precisely control the thickness and deposit films on highaspect-ratio surfaces.…”