Fabrication of single-phase ¦Å-GaSe films on Si(100) substrate by metal organic chemical vapor deposition

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• 作者：Chia-Chen Chang ; Jia-Xian Zeng ; Shan-Ming Lan ; Wu-Yih Uen ; Sen-Mao Liao ; Tsun-Neng Yang ; Wei-Yang Ma ; Kuo-Jen Chang
• 关键词：Gallium selenide ; Metal&ndash ; organic chemical vapor deposition ; Arsenic-passivation ; X-ray diffraction ; Scanning electron microscopy ; Photoluminescence
• 刊名：Thin Solid Films
• 出版年：2013
• 出版时间：2 September, 2013
• 年：2013
• 卷：542
• 期：Complete
• 页码：119-122
• 全文大小：3602 K

文摘

Single-phase ¦Å-gallium selenide (GaSe) films were fabricated on Si(100) substrate by metal organic chemical vapor deposition using dual-source precursors: triethylgallium (TEG) and hydrogen selenide (H₂Se) with the flow ratio of [H₂Se]/[TEG] being maintained at 1.2. In particular, an arsine (AsH₃) flow was introduced to the Si substrate before the film deposition to induce an arsenic (As)-passivation effect on the substrate. The crystalline structure of GaSe films prepared was analyzed using X-ray diffraction and the surface morphology of them was characterized by scanning electron microscopy. It was found that the film quality could be improved by the As-passivation effect. The optical properties of the films were studied by temperature dependent photoluminescence (PL) measurements. PL spectra obtained with different distributions and intensities favored for resolving the superior material quality of the films produced on the substrate with As-passivation compared to those produced on the substrate without As-passivation. The former was dominated by the excitonic emissions for the whole temperature range of 20-300 K examined, while the latter was initially dominated by the defect-related emission at 1.907 eV for a low-temperature range ¨Q 80 K and then became dominated by the weak excitonic emission band instead. The ¦Å modification of GaSe films prepared was further recognized by the Raman scattering measurements conducted at room temperature.