本論文成功利用化學氣相傳導法合成高品質二硫化鉬 (Molybdenum disulfide, MoS2)晶體，利用機械剝離法取得厚度控制在3-5 μm之MoS2薄片。透過氧電漿處理，經電荷中性點確認MoS2從n型半導體轉變為p型半導體。並利用拉曼光譜、X光光電子能譜圖及X光繞射分析，驗證氧被摻入MoS¬2中。利用氧電漿處理方法，在MoS2表面製作pn同質接面二極體，並找到其最佳處理條件，以此參數進行電學及光學相關量測。在電性量測方面，取得優異的電流-電壓特性曲線，其理想因子達1.9。之後進行半波整流量測，可以觀察到在交流訊號2 V且頻率在1000 Hz內有良好的整流效果。在光學特性量測方面，進一步製作MoS2光二極體元件，我們知道原始n-MoS2與全面氧電漿處理MoS2為光導體元件。將MoS2光二極體元件與上面兩種光導體元件，進行光電流、電導率與歸一化光響應度的量測，結果MoS2光二極體元件展現了相對優異的光學特性，經過分析發現其光電流增益，是由於其光伏效應機制。本實驗成功製作MoS2同質接面光二極體，除了具有優異的電學特性，也實現了光伏元件的製造，此研究成果對於MoS2相關光電元件的製造，提供一種穩定、有效率、非危險性且低成本的方式。

In this work, we used chemical vapor transport method (CVT) to synthesize Molybdenum disulfide (MoS2) single crystals. Through mechanical exfoliation, we controlled the thickness of MoS2 flakes from 1 to 3 μm. We transferred the characteristics of MoS2 from n-type to p-type with oxygen plasma treatment. After that, it was confirmed by using the charge neutrality point measurement (CNP). Raman spectroscopy, energy dispersive X-ray photoelectron Spectrometer (XPS), and X-Ray diffraction (XRD) were used to analyze that the oxygen plasma was effectively doped into MoS2. In order to fabricate a p-n homojunction diode, we designed a mask to define the doped area on the surface of MoS2 flakes, and the flakes were doped with oxygen for 20 minutes. Subsequently, we conducted measurements to determine electrical and optical properties of MoS2 flakes. In electrical measurement, the p-n homojunction diode demonstrated an excellent current-voltage characteristic curve, and its ideal factor was 1.9. The p-n homojunction diode also showed favorable rectifying behavior within 2 V and 1000 Hz within the half-wave rectification experiment. In order to determine the optical properties, we fabricated the homojunction photodiode devices, and pristine n-MoS2 and fully doped MoS2 photoconductor devices were fabricated as well for comparison. The MoS2 photodiode and the abovementioned two photoconductors were measured for photocurrent, conductivity, and normalized photoresponsivity. As a result, the MoS2 photodiode exhibited relatively good optical properties. After analyzing, we noticed that the increased photocurrent gain was due to its photovoltaic effect mechanism. In this experiment, the MoS2 homojunction photodiode was successfully fabricated by oxygen plasma treatment. It showed not only excellent electrical characteristics, but also achievement of photovoltaic devices.

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