本研究利用化學氣相傳導法成長硒化銦塊材，再以機械剝離法取得硒化銦薄片，先利用電荷中性點確認本質硒化銦為n型，再以掃描式電子顯微鏡觀察樣品表面樣貌，接著用氧電漿進行氧化處理以改變其半導體特性，分別用X射線光電子能譜儀、X射線能量散佈能譜儀與電荷中性點確認氧化效果，結果發現硒化銦在經過氧電漿處理後，可從n型轉變為p型，因此我們利用絕緣遮罩定義電漿處理的區域，以進行遮半氧電漿處理，製作出同質硒化銦pn接面二極體，並應用於半波整流電路中，量測發現硒化銦二極體在頻率1.5k Hz仍具有良好的整流功效。最後我們將硒化銦製作成三種光感測元件，分別為：本質硒化銦，經過氧電漿處理的外質硒化銦與遮半氧電漿處理的硒化銦二極體，以雷射波長405，532，633，808 nm進行光電流量測，雷射功率從0.1 mW到30 mW，並計算光電導率與光響應度，量測結果發現三種光感測元件都在808 nm得到最好的光電導率與光響應度，除此之外，我們也發現硒化銦二極體在光電導率與光響應度上均較本質與外質硒化銦佳，這是因為二極體之空乏區能夠抑制暗電流，光激發出的電子與電洞都能被內建電場掃出空乏區，總合成光電流，使得光電流增加。綜合本實驗所得結果，遮半氧電漿處理技術對於硒化銦的光電性能有明顯的改善，為相關領域的研究提供了新的思路和方法。

In this study, we used chemical vapor transport to synthesize bulk indium selenide (InSe) and then mechanically exfoliated to obtain InSe thin flakes. The material was characterized as n-type using the charge neutrality point (CNP) method and scanning electron microscopy (SEM) was used to observe the sample surface morphology. Oxygen plasma doping was performed to modify the semiconductor properties, and the doping effect was confirmed using X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDS), Raman spectrometry, and CNP measurements. Results showed that InSe could be transformed from n-type to p-type with oxygen plasma treatment. Therefore, we defined the treatment region using an insulating mask to fabricate homojunction InSe p-n diodes, which were then applied in a half-wave rectification circuit. Measurements revealed good rectification performance of the InSe diode at a frequency of 1.5 kHz. Finally, we fabricated three types of photodetectors using intrinsic InSe, oxygen plasma-doped extrinsic InSe, and InSe p-n diodes. The devices were tested with laser wavelengths of 405, 532, 633, and 808 nm, and the photoconductivity and photoresponsivity were calculated at laser powers ranging from 0.1 mW to 30 mW. Results showed that all three photodetectors exhibited the best photocurrent at 808 nm. Moreover, the InSe diode had better photoconductivity and photoresponsivity than intrinsic and extrinsic InSe, which was due to the depletion region of the diode suppressing dark current and the electrons and holes excited by light being swept by the built-in electric field to the depletion region to generate photocurrent.

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