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.