Hydrogen gas sensors based on nanocrystalline TiO2 thin films

Abstract

Abstract:Titanium dioxide thin films are extensively studied for applications in solid state gas sensor devices. Their gas sensing properties are strongly dependent on deposition technique, annealing temperature, film thickness and consequent properties like crystalline structure, grain size or amount of defects and impurities. In this work we report the gas sensing properties of TiO 2 thin films prepared by reactive magnetron sputtering technique and subsequently annealed at temperatures 600°C and 900°C. The films were exposed to different concentrations of H 2 gas up to 10 000 ppm. Their sensitivity to gas at various operating temperatures, ranging from 250°C to 450°C, was obtained by measuring their resistance. 07.07.Df, 68.47.Gh, 73.25.+i, 82.47 PACS (2008):

Investigating the influence of Al-doping and background humidity on NO<sub>2</sub> sensing characteristics of magnetron-sputtered SnO<sub>2</sub> sensors

“…All measurements were done in argon flow at a rate of 400 mL min −1 with a constant current of 1 × 10 −6 A. Considering the ideal cases, the gas mixing process in the chamber is governed by the differential equation as given in Haidry et al (2011). The gas mixing time τ mix can be estimated as the chamber volume divided by the flow rate.…”

Strong biaxial texture and polymorph nature in TiO2 thin film formed by ex-situ annealing on c-plane Al2O3 surface

“…The thin film growth procedure, the substrates and TiO 2 formation process are the same as for the gas sensing devices we have reported previously [34]. Thin film of TiO 2 has been grown by reactive DC magnetron sputtering from rectangular 99.99% Ti target in ArþO 2 (both of 99.995% purity) low pressure mixture of 0.5 Pa.…”

Fabrication of lotus-like Au@TiO2 nanocomposites with enhanced gas-sensing properties

“…Furthermore, they are nontoxic, environmentally friendly, cost-effective, excellently biocompatible and stable, which let TiO2 be a promising materials for use in gas sensors [17]. As a gas-sening material, TiO2 has been applied in the detection of CO [18], H2S [19], alcohol [20], H2 [21], NOx [22], etc. However, there still remains several drawbacks including long recovery time, high operating temperature (~300 o C) or low sensitivity at low temperature [23,24], which limit further applications of TiO2 in sensors.…”