Effect of Substrate Temperatures on the Structural and Optical Properties of Na-Doped ZnO Thin Films


ZnO thin films doped with Na have been prepared by chemical vapor deposition technique on the glass substrate at different temperatures (400, 450, 500 ˚C) for 20 min. By increasing the dopant Na from 0 to 20% in ZnO thin films were found to lead to pronounced changes in their structure. From optical properties the band gap energy of the Na-doped ZnO thin films is affected by increasing substrate temperatures and Na doping. X-ray diffraction (XRD) has shown that the maximum intensity peak corresponds to the (002) predominant orientation for ZnO films. Scanning Electron Microscope (SEM) images reveal the formation of Na-doped ZnO films having better crystalline behavior by increasing the substrate temperature at 500˚C. Energy dispersive X-ray analysis (EDXA) shows that the structure of ZnO contains Zn and O elements for undoped and Na for doping state