本實驗使用管型爐，進行水平定向凝固法，成功製備出單晶的三碘化鉻，接著我們分別針對樣品的外觀、化學組成、晶格結構、磁性量測、電性量測、光致螢光做了一系列的量測及探討，在外觀方面可以看到明顯的階梯狀結構，為二維材料的特徵，透過能量分散光譜儀及X光電子能譜儀，得知樣品由碘及鉻組成，且分布均勻，X光繞射儀說明了其為三方晶系，接著使用超導量子干涉儀量測樣品磁性，其為鐵磁性並具有磁晶異相性，磁相變溫度為~61 K，在環境溫度為2K、c軸與外加場平行時，矯頑力達0.265 Oe，而I-V變溫電性量測，則說明樣品電性特徵傾向於半導體，最後變溫量測了光致螢光，推算樣品能隙為1.37 eV，溫度改變時其特徵峰位置並無改變，說明樣品對於溫度有穩定性的。

The horizontal directional solidification method (HDSM) was used to synthesize flakes of single crystal two-dimensional (2D) CrI3 layers. Furthermore, we studied the morphological, structural, electronic, chemical, magnetic, and electronic properties of the single crystal 2D CrI3 layers. Morphologically we clearly see the stacks of step-like layers of CrI3. The crystal structure of the 2D CrI3 layers found to be a trigonal system. The chemical composition of 2D CrI3 layers is confirmed using energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. Photoluminescence (PL) spectroscopy show the enhancement of the PL intensity with the incident laser power and reducing temperature. Using PL spectroscopy, the band gap of the 2D CrI3 layers determined to be 1.37 eV. The magnetic studied show the ferromagnetic anisotropy of CrI3 where c-axis is perpendicular to the plane of 2D layers. The critical temperature of the magnetic phase change is found to be of ~61 K. The current-voltage properties at various temperature reveals the semiconductor nature of the CrI3 layers.

第一章 導論與文獻回顧 1
第二章 實驗流程及製備儀器 17
第三章 分析儀器 23
第四章 結果與討論 33
第五章 結論 49

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