Electron Exchange Process Control Between Silver Nanoparticles and Metal-Oxides for Highly Selective Gas Detection

A highly-selective gas detection strategy is described based on the continuous iteration method of various kinds of nanowires (WO3, TiO2, SnO2, CuO, and ZnO) growth at a wafer level and the catalytic functions of silver nanoparticles. The catalytic process occurring on the silver and the nanowires depended on the magnitude of barrier height at the interface. It determined the electron exchange rate across the interface and the resulting band bending was changed near the interface when it was exposed to gases, resulted in different gas responses among the nanowires. The sensor array with palladium and silver nanoparticles was tested for the ability to distinguish between the hydrogen, carbon monoxide, and nitric oxide with detection limits ranging from sub-ppm to ppm levels, enabled the gas responses to be separated into three classes using linear discriminant analysis.