Study On Sensitive Characteristics Of Formaldehyde In Cd - Doped ZnO Thin Films

Currently, formaldehyde gas time does not affect people’s lives and health, so the measurement of formaldehyde has been growing research, detection of formaldehyde in all aspects of life are used. In a study of formaldehyde detected, you can take advantage of the sensitive nature of sensitive material to detect the concentration of formaldehyde and harmful factors on people in the study of gas-sensitive materials, it has been not only to enhance the selectivity and sensitivity characteristics of conventional gas, also hopes to improve the high working temperature control for sensitive material, that is, developed a gas-sensitive materials can work at room temperature. In the study of gas-sensitive material, doping can improve the sensitive nature of gas-sensitive material. Therefore, in this paper, we study an under ultraviolet irradiation of sensitive material, and the sensitive material doping, ie doping of ZnO sensitive material Cd, ZnO doped sensitive film can operate at room temperature, without adding heating electrodes. Here we choose a wavelength of 370 nm ultraviolet as an excitation source, the use of ZnO thin films prepared by sol-gel method and Cd-doped ZnO films. By controlling the intensity of ultraviolet radiation, measured concentrations of Cd-doped ZnO different sensitive film sensitivity, in order to select the optimal doping ratio. After measuring selectivity, repeatability and response time.Through our paper can be concluded, Cd-doped ZnO films is a promising sensitive membrane, UV irradiation intensity of 1.53 mW / cm2 obtained when doped with 2.6%, the best sensitivity.