Study on the optical absorption and green emission of ZnO phosphors by varying Al doping contents

The blue band optical absorption and green luminescence of ZnO phosphors doping with aluminum are systematic studied. The Al content is varied from 0.01 at.% to 1 at.%. SEM images illustrated that Al doping can effectively suppress the ZnO grain growth. XRD results clearly manifest that the Al solubility limit in ZnO is around 0.1 at.%. It is also found that the E-1 (LO) vibration mode in the Raman spectra exhibits a good correlation with the blue band optical absorption and green photoluminescence. The results revealed that both V-O(0) and V-O(+), can give rise to the E-1 (LO) vibration mode. We conclude that the V-O and O-i defects are the dominant reason of the green photoluminescence in ZnO phosphors, in oxygen-deficient and oxygen-rich conditions, respectively. (c) 2012 Elsevier B.V. All rights reserved.