Effect of SnO2 coating to the properties of ZnO nanorod array

Abstract

Tin oxide coated zinc oxide nanorod arrays (SnO2/ZnO) were prepared using two step sol-gel processes in which the ZnO nanorod arrays were initially grown on ZnO seed layer coated glass substrate. Then, a thin layer of SnO2 is coated on the nanorod arrays using spin coating method. The structural and optical properties of the films were investigated using FESEM, XRD and UV-vis, respectively. The surface morphology of the films showed that the nanorod arrays are covered by rough layer of SnO2. The average diameter of ZnO nanorods is about 80 nm. The XRD plot indicates that the film consist of hexagonal wurtzite ZnO and rutile SnO2 structure. Besides, the addition of SnO2 layer leads to diffraction angle shifting at (002) plane orientation. The optical properties of films displayed that the SnO2/ZnO induced lower transmittance film at visible region than that of bare ZnO nanorod arrays. Besides, the SnO2/ZnO film exhibited high optical band gap energy of 3.35 eV.