کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1608163 | 1516243 | 2015 | 6 صفحه PDF | دانلود رایگان |
• First observation of self-organized growth of ZnMgO nanocolumns on r-plane Al2O3 without any catalyst is demonstrated.
• Nanocolumns exhibit high crystallographic quality and they are tilted 62° to the substrate.
• Deposition of a low temperature ZnO buffer layer results in planar growth of the structures.
• The MQWs reveal excitonic near-band edge emission at low and room temperatures.
Growths of ZnMgO/ZnO/ZnMgO multiple quantum well (MQW) structures were performed on semi-polar r-plane sapphire substrates by molecular beam epitaxy. It has been shown that it is possible to grow self-organized ZnMgO nanocolumns with MQW structures at a temperature of 550 °C without employing a catalyst. The nanocolumns are symmetrically tilted at an angle of 62° to the substrate surface. Deposition of a low-temperature (450 °C) ZnO buffer layer prior to the growth of ZnO/ZnMgO MQWs results in good quality planar structures. The crystalline quality of the nanostructures was characterized by X-ray diffraction and scanning electron microscopy. Luminescence properties of ZnO/ZnMgO heterostructures and MQWs were studied. The luminescence was dominated by localized exciton emissions below 100K, while free exciton recombination was the most intense emission at temperatures above 100 K.
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Journal: Journal of Alloys and Compounds - Volume 650, 25 November 2015, Pages 256–261