Preparation of one dimensional Bi₂O₃-core/ZnO-shell structures by thermal evaporation and atomic layer deposition

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• 作者：Sunghoon Park ; Jina Jun ; Hoyun Woo Kim ; Chongmu Lee
• 关键词：A. Bi₂O₃ ; A. ZnO ; C. One-dimensional structure ; D. Thermal evaporation
• 刊名：Solid State Communications
• 出版年：2009
• 出版时间：February 2009
• 年：2009
• 卷：149
• 期：7-8
• 页码：315-318
• 全文大小：1562 K

文摘

One dimensional(1D) Bi₂O₃-core/ZnO-shell structures with uniform layer thicknesses were prepared by using a two step process consisting of thermal evaporation of Bi₂O₃ and ALD of ZnO. Highly straight 1D Bi₂O₃ structures were synthesized by thermal evaporation of Bi powders on c-plane Al₂O₃ substrates and then ZnO layers were coated on them by ALD.

SEM analysis shows that the oxygen partial pressure must be precisely controlled to obtain straight Bi₂O₃ nanowires. According to the TEM analysis results the Bi₂O₃-core is a pure tetragonal β- Bi₂O₃ phase single crystal, while the ZnO-shell is amorphous. Photoluminescence (PL) measurement of the ID core/shell nanostructures under excitation at 325 nm indicates that the critical number of ALD cycle for which a transition from a violet emission characteristic of Bi₂O₃ to UV and green–yellow emissions characteristic of ZnO occurs is less than 10, suggesting that the wavelength of the emission changes abruptly with an increase in the number of ALD cycle.