Gas Sensing Properties of Formaldehyde Sensor Based on Zn-, Cu-Doped NiO Thin Film

摘要

Formaldehyde (HCHO) gas sensors have been prepared with pure NiO, Zn-doped NiO and Cu-doped NiO thin films deposited on Si substrates by radio-frequency (RF) reactive magnetron sputtering. The changes of response were studied at different work temperatures (100°C ～450°C ) and different formaldehyde concentrations( 100 ppm ～ 400 ppm). Doping with Zn, the gas response of NiO thin film increased from 36.7% to 51.3% for 400 ppm HCHO. The sensitivity was also improved for the Zn-doped samples for a series of HCHO concentrations ranging from 100 ppm to 400 ppm. The reasons for the significant enhancement of HCHO response by doping Zn and Cu into NiO films were discussed.