Effects of thermal annealing on the performance of Al/ZnO nanorods/Pt structure ultraviolet photodetector

ZnO nanorod arrays were fabricated on ZnO coated glass substrate by hydrothermal method. Schottky barrier ultraviolet photodetectors (PDs) were obtained by sputtering Pt electrode and evaporating Al electrode on the top of ZnO nanorod arrays with thermal treatment. It is illustrated that Schottky contacts at the electrode/ZnO NRs interface were formed at the annealing temperature of 300 degrees C and above. When annealing temperature was up to 300 degrees C, the performance of the PDs was improved with the great decrease of response and recovery times. At the forward bias of 2V. the Schottky contact PDs showed the biggest responsivity and the best detectivity at the annealing temperature of 300 degrees C. For annealing temperature at 300 degrees C and above, the responsivity decreases with increasing annealing temperature and the ratio of detectivity (D-254* to D-546*) was calculated as high as 10(3) for all PDs annealed at 300 degrees C and above. (C) 2011 Elsevier B.V. All rights reserved.