以分子束磊晶成長二維層狀硒化鎵之結構與拉曼光譜分析

Structure and Raman Spectra Analysis of 2D-Layered Gallium Selenide Grown by Molecular Beam Epitaxy

顏利甄(Li-Jhen Yan)

指導教授 ： 周武清

國立交通大學/理學院/電子物理系所/碩士(2019年)

摘要

以分子束磊晶於藍寶石、氮化鎵與砷化鎵基板上成長二維材料硒化鎵薄膜，並透過拉曼光譜分析其光學特性。嘗試改變硒化鎵成長於藍寶石基板上的基板溫度、硒與鎵流量比與磊晶時間等參數，觀察不同成長條件下的硒化鎵磊晶形貌與拉曼光譜。硒化鎵的金字塔狀結構說明其生長機制為逐層生長，這樣的結構會隨著磊晶時間增加而發生改變，從金字塔狀轉變為閉環三角形結構。閉環三角形結構為同心多層生長所導致，對應到拉曼光譜觀察到的硒化鎵E_2g^1模態簡併解除，說明面內方向應力的存在可能導致硒化鎵的生長機制改變。

關鍵字

分子束磊晶 ； 二維材料 ； 硒化鎵 ； 拉曼光譜

並列摘要

Two-dimensional material gallium selenide (GaSe) films were grown on sapphire, gallium nitride and gallium arsenide substrates by molecular beam epitaxy. The optical properties of GaSe films were analyzed by the Raman spectroscopy. The Effects of growth conditions, different substrate temperatures, Se/Ga flux ratio and epitaxial time, on the epitaxial morphology and Raman spectrum were studied. The pyramidal structure of GaSe indicates that its growth mechanism is layer-by-layer growth. A structure change, from pyramid to closed-loop triangular structure, with the increasing epitaxial time was observed. The closed-loop triangular structure is caused by the concentric multilayer growth, which accompanies a lift of the GaSe E_2g^1 mode degeneracy in the Raman spectrum. It implies the presence of in-plane stress, which results in the change of growth mechanism of GaSe.

並列關鍵字

MBE ； 2D Material ； GaSe ； Raman Spectra

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