Study of Effect Concentration of Ethanol Vapor on Sensing Properties of Nano Powders Zinc Oxide Films

Abstract

The purpose of this research is study the effect concentration of ethanol vapor on Sensing Properties of nano powders Zinc Oxide thick films. So three thick films have been prepared by the chemical painting method from Zinc Oxide nano powders as the source compound their dimensions of particle about (166.47, 34.7, 36.23nm), nano powders of Zinc Oxide are prepared by milling in a high energy ball mill for various spans of time (1-18h) on cleaned glass substrates under limited thermal conditions. The sensitivity depends on adsorption reactions and chemical or physical desorption, and photo absorption reactions, and chemical reactions that occur on the surface or within the sensor material. These reactions lead to specific physical changes in the sensor which can be analyzed. This identification process can be carried out using several different principles such as conductivity, electrical polarography, electrochemical activity, photo and magnetic properties, and electrical isolation properties. .The films have been investigated for their sensing properties relating to 200ppm ethanol vapor adsorption using the (I–V) characteristics in air and in the presence of ethanol vapor using KEITHLEY 237 device .The temperature of the films has been changed from 50°C to 350°C we note improving in sensitivity of three films with increasing temperature until specific temperature degree, then we note that the film which dimensions 34.7nm has high sensitive among three films at 250°C .We note that improves the sensitivity of the film with an increased concentration and the operating temperature of film has decreased with increased concentration

Keywords: Zinc Oxide (ZnO), Ethanol Vapor, Sensing properties.