Effect of SnO_2 Coating to the Properties of ZnO Nanorod Array

摘要

Tin oxide coated zinc oxide nanorod arrays (SnO_2/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 Sn02 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 SnO_2. The average diameter of ZnO nanorods is about 80 nm. The XRD plot indicates that the film consist of hexagonal wurtzite ZnO and rutile SnO_2 structure. Besides, the addition of SnO_2 layer leads to diffraction angle shifting at (002) plane orientation. The optical properties of films displayed that the SnO_2/ZnO induced lower transmittance film at visible region than that of bare ZnO nanorod arrays. Besides, the SnO_2/ZnO film exhibited high optical band gap energy of 3.35 eV.