Luminescent properties of ZnO microstructures grown on Au/Si substrate

ZnO microstructures have been grown on gold coated silicon substrate at 600°C by chemical vapor deposition. A rough surface showing two different crystal morphologies was observed in the scanning electron microscope. The characteristic crystallographic plane (0002) of the zinc oxide was identified using the XRD pattern. To compare the luminescence properties of the deposit, an air annealing was performed at 100°C, 300°C and 500°C. The trapping levels produced on this oxide were studied by the thermoluminescence after beta radiation. The room-temperature photoluminescence spectra of the samples show two peaks related with the edge band emission and the green band typical of the ZnO. In contrast, the room-temperature cathodoluminescence spectra present a dominant edge band emission.