ENHANCEMENT OF GAS SENSITIVITY FOR ZNO:SIO2 THIN FILMS PREPARED BY PULSED LASER DEPOSITION TECHNIQUE
In this paper,ZnO was mixing by various concentrations of SiO2 (5,10,15) w%. The mixture was deposited on glass substrate by Pulsed Laser Deposition (PLD) technique under high vacuum (10-2 Torr) using constant prepared conditions such as: Nd:YAG wavelength 1064nm, Laser Pulse energy (100-1000) mJ, Pulse duration=10ns and Repetition frequency 6 Hz.The thickness of the prepared films was about ( 250) nm. The structure of the thin films was examined by using (XRD) analysis.The results showed that there was a decrease in the peaks of zinc oxide with gradual peaks of the zinc silicate compound at angles 2Ө (25̊,38̊,49,66̊) due to increase in silicon oxide concentrations rates. The optical properties of thin films include the spectral absorption and transmission recording were studied at the wavelength range (200- 1100) nm. Some of the optical constants, including absorption coefficient, and energy gap are calculated.The results show that an increases in the absorption coefficient after and decreses in the energy gap after the doping with SiO2 particles. In this paper we studied the effect of SiO2 ratio on the sensitivity of (NO2) gas sensor. It is found that the increase in the sensitivity after doping process with SiO2 particles.
Keywords: Pulsed Laser Deposited, Structural Properties, Optical Properties, Gas Sensor.