Effect of ammonia/zinc nitrate molar ratio on structural and optical properties of Al and Sb codoped ZnO nanorod ordered array thin films

Al and Sb codoped ZnO nanorod ordered array thin films were synthesized on glass substrates with a ZnO seed layer via hydrothermal method with different molar ratios of ammonia/zinc nitrate. It is found that the thin films with molar ratio of 8:1 consist of nanorods growth vertically oriented with ZnO seed layer, and the nanorods with an average diameter of 27.8 nm and a length of 1.02 mu m consist of single crystalline wurtzite ZnO and grow along (0 0 2) plane. Raman scattering analysis demonstrates that the broad peak (similar to 580 cm(-1)) shifts to red direction, while the redshift arrives at a maximum of 15 cm(-1) with molar ratio of 8:1. Room temperature photoluminescence reveals that the increase of emission property of ZnO film is caused by the point defect (Zn-i, V-Zn, V-O, O-Zn) generated due to the adjustment of the molar ratio of ammonia/zinc nitrate. (C) 2012 Elsevier B.V. All rights reserved.