本篇文章的主要工作內容是在於利用化學氣相沉積法(CVD)合成WS2以及WSe2，CVD的製程相當複雜，變數相當多且都會互相影響，本研究藉由改變實驗參數，觀察不同參數對結晶的影響，試著釐清並深入討論提出結晶的成長機制，包括還原氣氛(氫氣)、氣流型態、反應物的添加量以及反應物的位置等，進一步最佳化實驗參數去合成獨立或大面積的單層結晶，並將單層結晶做成元件量測材料的電學性質以及光電性質，最後以合成純相材料WS2、WSe2時所歸納的成長機制，實現WS2-WSe2混相結構的合成，希望能結合此二種材料優異的特性進一步去開發出能廣泛應用的半導體元件，透過參數調整，我們得到不同混合比例的混相結構，發現不同混合比例會使材料的光致螢光放光波長改變，也代表材料的能隙會因混合比例不同而改變。

In this research, we used chemical vapor deposition to synthesize monolayer WS2、WSe2.The impact of growth parameters of WS2 and WSe2 was investigated , such as gas flow rate , reducing atmosphere(H2), amount of precursor .The high quality of monolayer WS2 and WSe2 was confirmed by optical microscopy ,atomic force microscopy(AFM) , photoluminescence (PL) and Raman spectroscopy. The growth mechanism was discussed and proposed. In addition, we report on electronics and optoelectrons properties based on back-gated field-effect transistors. The device of WS2 exhibited a excellent photoresponsivity of 63.8A/W. On the other hand, device of WSe2 is ambipolar , could be turned into either n-type or p-type electrical behavior. Finally, we show that hybrid WS2-WSe2 can be synthesized by chemical vapor deposition. PL of hybrid could be tunable by controlling the amount of precursors.

目錄 1
圖目錄 3
第一章 研究動機 7
第二章 文獻回顧 9
2-1 過渡金屬硫族化合物 9
2-1-1 晶體結構 9
2-1-2 能帶結構. 9
2-1-3 TMD場效電晶體特性 10
2-1-4 光電性質 11
2-2 過渡金屬硫族化合物的合成 11
2-2-1 機械剝離法 11
2-2-2 化學離子插層 12
2-2-3 物理氣相沉積 12
2-2-4 化學氣相沉積 13
2-3 CVD合成二維材料之成長機制 13
2-3-1 溫度效應 13
2-3-2 氫氣對結晶的影響 14
2-3-3 螺旋差排造成的島狀生長 15
2-4 二維材料之檢測技術 15
2-4-1 拉曼光譜分析 15
2-4-2 光致螢光光譜分析 16
2-4-3 歐傑電子分析 17
第三章 實驗方法 28
3-1 實驗大綱 28
3-2 實驗系統 28
3-2-1 試片處理 28
3-2-2 實驗步驟 29
3-3 材料分析與量測 30
3-3-1 光學顯微鏡 30
3-3-2 拉曼光譜分析 30
3-3-3 光致螢光光譜分析 30
3-3-4 歐傑電子分析 31
3-3-5 電性與光電性質量測 31
第四章 二硫化鎢的合成與分析 36
4-1 製程參數對二硫化鎢生長的影響 36
4-1-1 不同生長位置對結晶的影響 36
4-1-2 氣流對結晶的影響 38
4-1-2 還原氣氛(氫氣)對二硫化鎢的影響 39
4-1-4 硫添加量對結晶的影響 39
4-1-5 二次相 40
4-1-6 硫進入時間對結晶的影響 41
4-1-7 總結 42
4-2 單層二硫化鎢的電性與光電量測 43
第五章 二硒化鎢的合成與分析 56
5-1 製程參數對二硒化鎢(WSe2)生長的影響 56
5-1-1 還原氣氛(氫氣)對合成二硒化鎢的影響 56
5-1-2 硒進入時間對結晶的影響 56
5-1-3 島狀生長 57
5-1-4 最佳化參數 58
5-2單層二硒化鎢的電性量測 59
第六章 硫硒化鎢混合結構的合成與分析 63
6-1 硫硒化鎢混合結構的合成 63
6-2 硫硒化鎢混合結構的分析 64
6-3 控制硫/硒進入系統的時間 65
6-3 未來工作 65
第七章 結論 71
參考文獻 72

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