Gas Sensitivity and Morphologically Characterized of Nanostructure CdO Doped In2O3 Films Deposited by Pulsed Laser Deposition

Abstract

In this work, films have been grown under various deposition conditions in order to understand the effect of processing on the film properties and to specify the optimum condition, different indium oxide (In2O3) contents (0, 1%, 3%, 5% and 7%) using double frequency pulse laser beam (Q-switching) Neodymium-yttrium aluminum garnet (Nd:YAG (wavelength 532 nm)), to deposit Cadmium Oxide: Indium oxide (CdO:In2O3) films on Aluminum Oxide (sapphire α-Al2O3 (006)) and quartz substrates. The structural properties of samples were investigated by using of surface morphology of the deposits materials has been studied by using atomic force microscopy (AFM). The samples are displayed granular structure. It was found that the grain size decreases with increasing of doping concentration ratio, the smallest grain size equal to (79.11 nm) and (82.99 nm) were achieved at ratio of doping (7%) for quartz and sapphire α-Al2O3 substrate, respectively. The sensitivity of undoped and doped CdO samples toward Nitric dioxide (NO2) gas in air ambient has been measured in the home building system. All samples were tested at mixing ratio (3% NO2:air). The optimal operating temperature is found to be 200-225°C for pure CdO and decreases to 175-200°C for samples. The maximum sensitivity is equal to (263.97%) with response time (13.5 s) and recovery time (15.5 s) are achieved at (3%) doping concentration level for sapphire α-Al2O3 substrate.