Selective NO/sub 2/ gas sensing characteristics of sol-gel prepared MoO/sub 3/-WO/sub 3/ thin films

摘要

Molybdenum trioxide - tungsten trioxide (MoO/sub 3/-WO/sub 3/) binary metal oxide thin films have been prepared by the sol-gel process. The films were deposited using the spin coating technique onto alumina substrates with interdigital electrodes and single crystal silicon substrates for electrical and micro characterization. Scanning Electron Microscopy (SEM) showed MoO/sub 3/-WO/sub 3/ film morphology composed of MoO/sub 3/ needle like grains and WO/sub 3/ spherical grains when annealed at 450/spl deg/C. The films exhibited selective gas sensing characteristics at an operating temperature of 300/spl deg/C towards nitrogen dioxide (NO/sub 2/).