Fabrication ofCO2/O2 Gas Sensorusing Zn Othin films Synthesizedvia Sol- gel method

Thin film of ZnO was synthesized on a glass substrate via sol-gel method. The crystal structure and surface morphology was studied، using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The size of crystalline particles formed on the surface were calculated using Scherrer''s equation and the X''pert High score software، and was estimated around 30 nm. Using synthetic coating، metal oxide gas sensors were fabricated and the sensitivity of the sensor to the two common gases of O2 and CO2 were analyzed. The results showed that the porous coating of zinc oxide is very sensitive to the gases. Also، the response time for the two gases، were calculated. Response time for CO2 was twice of the O2، and about 12 seconds.