Investigation of gas detection characteristics of Cd additive ZnO samples

The developments in the industry with the development of technology cause a rapid production potential in the society and this creates a greenhouse effect with the excessive accumulation of gases such as CO2, CH4, N2O, which are released into the atmosphere by industrial systems in large quantities. Detection and monitoring of the amount of toxic gas has become very important for environmental safety worldwide. For these important reasons, gas sensors that can detect the CO2 gas concentration were developed in this thesis study. In order to examine the effect of the additive Metal and its ratio on the gas detection properties, Metal oxide structures were grown by chemical bathing method (CBD) for the synthesis of pure ZnO and Cd doped (Zn1-xCdxO, x = 0,01, 0,03, 0,05, 0,07) thin films. characterization was done. Zinc acetate dihydrate Zn (CH3CO2) 2.2H2O, cadmium acetate dihydrate C4H6CdO4 and ammonium hydroxide solution NH4OH were used as zinc source, cadmium source and complexing agent, respectively, to synthesize the films. The structural and optical properties of the films were investigated by X-ray diffraction device (XRD), scanning electron microscope (SEM) and Raman analysis. In Cd-doped thin films, the sensor response was determined by the change in the resistance of the film in the presence and absence of CO2 gas. Among the thin films produced, the 3% cadmium doped sensor showed the highest sensitivity for 100 ppm CO2 gas concentration at room temperature with a value of 8,7 %. In addition, dielectric and impedance analyzes were performed in the temperature range of 300 K and 700 K.