Highly textured ZnO thin films: An economical fabrication, doping by Mn~(2+) and Sn~(2+) and approachment for optical devices

摘要

Fabrication of high quality zinc oxide thin films and analysis on its physical, chemical properties have applications in opto-electronic devices, UV laser, microelectronics and micro-machining schemes. Highly textured ZnO thin film with a preferred (002) orientation was prepared by two-stage chemical deposition (TSCD) using an aqueous solution containing zinc complex on a soda-lime glass substrate. From the results obtained, it can be shown that the preferred orientations of the film microcrystal changes with the doping process. The film was characterized by X-ray diffraction (XRD), SEM, EDAX, optical technique, Fourier transform infrared spectroscopy (FTIR) in order to qualify its suitability for application in commercial devices. Effect of number of dipping on growth rate and properties of the undoped and doped-thin film was investigated. XRD patterns revealed the formation of polycrystalline textured thin films containing nano-grains. The chemical compositions of the thin films were determined by EDAX and FTIR methods. SEM reveals the presence of uniform adherent thin film. Increasing in grain size (R_x) of undoped and doped thin films were observed, while increasing the number of dipping. Optimized films allowed a 96 percent average transmission in the visible range. The mean band gap measured from the transmission spectrums of the undoped samples was 3.25 eV. The transmission curves of doped samples fluctuated with increasing the wavelength and this is due to interference of the light in the film itself. Feasibility of the prepared films for application in optical and UV laser devices was assessed by optical systems.