Effect of Oxygen Admittance Temperature on the Growth of ZnO Microcrystals by Thermal Evaporation Technique
- 作者：K.M.K. Srivatsa ; kmk_srivatsa@mail.nplindia.ernet.in ; Deepak Chhikara ; M. Senthil Kumar
- 关键词：ZnO microcrystals ; Thermal evaporation ; Scanning electron microscopy ; Transmission electron microscopy ; Room temperature photoluminescence
- 刊名：Journal of Materials Science & Technology
- 出版年：2012
- 期刊代码：pc165_10050302
- 类别：ms
- 出版时间：April, 2012
- 卷：28
- 期：4
- 页码：317-320
- 文件大小：436 K
摘要
Hexagonally well-faceted microcrystals of ZnO have been grown by thermal evaporation of Zn powder in oxygen ambient at 700 掳C under atmospheric pressure. It has been observed that the properties (size and quality) of ZnO microcrystals have a strong dependence on the reactor temperature at which the oxygen gas is admitted into the growth zone. The microcrystals grown with oxygen admittance at 450 掳C have a length of 1 渭m and a diameter of 0.75 渭m while that grown with oxygen admittance at 600 掳C have a length of 1.5-2 渭m and a diameter of 1 渭m. Room temperature photoluminescence spectra show a ultraviolet (UV) emission peak at 385 nm with a green band emission at around 500 nm. The UV-to-green band emission ratio for the microcrystals grown with oxygen admittance at 450 掳C is observed to be 1.25 and the ratio decreases to 0.45 for the sample grown with oxygen admittance at 600 掳C.