本研究使用布里茲曼法成長硒化鎵(Cd=1%)塊材，並利用機械剝離法取得硒化鎵(Cd=1%)薄片，利用氮電漿處理改變其半導體特性，經過電荷中性點量測和FET載子量測發現成功使硒化鎵(Cd=1%)從p型半導體轉變為n型半導體材料。並使用掃描式電子顯微鏡，拉曼光譜儀，光激發螢光光譜，X射線光電子能譜儀對硒化鎵(Cd=1%)進行特性分析。接著使用玻璃基板作為遮罩定義電漿處理範圍，將一半的硒化鎵(Cd=1%)遮半做電漿處理，製備出同質pn接面二極體，並量測出二極體特性曲線，且在110 W氮電漿處理的同質pn接面發現最佳n值，n值為2.19，並將此應用於半波整流電路中，量測結果在頻率1-1k Hz內皆有良好的整流效果。在光感測元件方面，製作了三種元件，分別為本質硒化鎵(Cd=1%)，經過全面氮電漿處理的硒化鎵(Cd=1%)和遮半氮電漿處理的硒化鎵(Cd=1%)二極體，進行光電流，光電導率，歸一化光響應度的量測，結果顯示硒化鎵(Cd=1%)二極體在光電導率和歸一化光響應度皆為最佳，這是因為二極體在逆向偏壓下能使空乏區變寬，抑制暗電流，且光激發的電子-電洞對在內建電場的指引下快速分離，使光電流上升。本研究結果顯示，硒化鎵(Cd=1%)的光電性能可透過製作遮半氮電漿處理同質pn二極體來增強，且是低成本，高效率和非危險性的方式。

In this study, gallium selenide (Cd=1%) bulk was grown by using the Bridgman method, and flake of gallium selenide (Cd=1%) were obtained through mechanical exfoliation. Nitrogen plasma treatment was employed to modify its semiconductor properties. Measurements of the charge neutrality point (CNP) and FET revealed a successful transition of gallium selenide (Cd=1%) from a p-type to an n-type semiconductor material. Characterization of gallium selenide (Cd=1%) was conducted using scanning electron microscopy (SEM), Raman spectrometer, photoluminescence (PL), and X-ray photoelectron spectroscopy (XPS). Next, a glass substrate was used as a mask to define the plasma treatment area, and half area of the gallium selenide (Cd=1%) was plasma-treated to prepare a homojunction pn diode. The diode characteristic curve was measured, and the optimal ideal factor (n) of 2.19 was found in the homojunction pn diode treated with 110 W nitrogen plasma. This diode was applied in a half-wave rectifier circuit, showing good rectifying performance across the frequency range of 1-1k Hz. In the optical measurement, three types were fabricated: intrinsic gallium selenide (Cd=1%), gallium selenide (Cd=1%) with nitrogen plasma treatment, and half nitrogen plasma-treated gallium selenide (Cd=1%) pn diode. Measurements of photocurrent, photoconductivity, and normalized photoresponsivity indicated that the gallium selenide (Cd=1%) pn diode exhibited the best performance in terms of photoconductivity and normalized photoresponsivity. This is attributed to the widening of the depletion region under reverse bias, which suppresses dark current and allows rapid separation of photoexcited electron-hole pairs under the influence of the built-in electric field, leading to an increase in photocurrent. The results of this study demonstrate that the photoelectric performance of gallium selenide (Cd=1%) can be enhanced by fabricating a homojunction pn diode through partial nitrogen plasma treatment. This method is low-cost, efficient, and non-hazardous.

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