P1.0.13 Highly sensitive ZnO−SnO2 nanocomposite H2 gas sensor

Abstract

Thin film sensors based on SnO 2 , ZnO and ZnO-SnO 2 nanocomposite have been fabricated using pulsed laser deposition technique.The prepared sensors were studied for their response characteristics towards 500 ppm H 2 gas.The nanocomposite sensor structure (ZnO-SnO 2 ) shows an enhanced response of about 8.8×10 2 as compared to that obtained (7 and 8) for bare ZnO and SnO 2 thin film sensors respectively at a relatively lower operating temperature of 160°C.The nanocomposite sensor shows an improvement in response and recovery speeds compared to that of pure ZnO film sensor, though the results are slightly degraded in comparison to the bare SnO 2 thin film based sensor structure.The origin of enhanced response of ZnO-SnO 2 composite sensor is attributed to the modulation of depletion region width at the n-n heterojunction besides the enhanced oxygen adsorption.The high sensing response obtained at low operating temperature for ZnO-SnO 2 composite sensor is attractive for efficient detection of H 2 gas.