Template-Free Synthesis of Highly Uniform α-GaOOH Spindles and Conversion to α-Ga2O3 and β-Ga2O3

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• 作者：Hai-Sheng Qian ; Poernomo Gunawan ; Yun-Xia Zhang ; Guo-Feng Lin ; Jian-Wei Zheng ; Rong Xu
• 刊名：Crystal Growth & Design
• 出版年：2008
• 出版时间：April 2008
• 年：2008
• 卷：8
• 期：4
• 页码：1282 - 1287
• 全文大小：1165K
• 年卷期：v.8,no.4(April 2008)
• ISSN：1528-7505

文摘

Monodispersed single crystalline α-GaOOH spindles have been prepared via a simple wet-chemical route at 60 °C, in which GaCl₃ was used as the gallium source and ammonia as the alkali. The α-GaOOH spindles obtained at pH values of 10.0 and 11.0 have a hierarchical layered nanostructure and are comprised of many nanoplatelets. The investigation of the products formed at early growth stages indicates that the spindles are formed by a self-assembly process via oriented attachment. During this process, the pH value and the ammonia molecule have great influence on the morphology of the final products. Smooth prism-like α-GaOOH crystals were obtained at a lower pH value of 8.0 when ammonia was used or when ammonia was replaced by ethylenediamine at pH values of 8.0 and 10.0. The single-phase α-Ga₂O₃ and β-Ga₂O₃ spindles can be obtained by thermal treatment of the α-GaOOH spindles at 600 and 900 °C, respectively. The morphological characteristics of the pristine α-GaOOH spindles are well maintained in the oxide products in terms of good dispersion, size uniformity and layered nanostructure. The β-Ga₂O₃ spindle product exhibits a strong blue luminescence emission under the excitation wavelength of 250 nm.