本論文主要探討利用化學氣相傳導法(chemical vapor transport)成長之三硒化二銦 (In2Se3) 層狀半導體奈米結構之光電導及電傳輸特性。利用機械剝離法將三硒化二銦單晶分離成二維奈米結構，並利用聚焦式離子束(focus ion beam)製作二維奈米結構之白金電極。對三硒化二銦奈米薄片進行光電導量測，發現其具有明顯的光電流反應，且隨著光強度增加，光電流也表現出非線性的增加。同時在相同的綠光雷射波長條件下，藉由比較不同層狀半導體，發現三硒化二銦奈米結構有著最佳的光反應率(responsivity)及光電導增益(gain)。進而去記算出歸一化增益(normalized gain)，發現三硒化二銦歸一化增益至少大於其它層狀半導體奈米結構兩個數量級。此外在不同波長照射下，發現三硒化二銦奈米薄片對紅外光具有較佳的光電流反應。藉由環境變化之光電導量測，顯示三硒化二銦遵循氧敏化光電導機制(oxygen-sensitized)。其造成三硒化二銦奈米薄片具有較佳的光電導特性之物理機制也將在本論文中探討。

Photoconduction and electronic transport properties in the direct-bandgap layer semiconductor of hexagonal diindium triselenide (In2Se3) grown by chemical vapor transport (CVT) have been investigated. The In2Se3 layer nanostructure devices were fabricated using focused-ion beam (FIB) to deposit platinum (Pt) as the contact metal. We observed that the photocurrent of In2Se3 nanosheets increases nonlinearly with an increase at light intensity. Notably, under the same excitation wavelength condition, the In2Se3 nanosheets show the optimal responsivity compared to most of the layer semiconductor nanostructures. The normalized gain values, which defines the inherent photocurrent collection efficiency, of the In2Se3 nanosheets are over two orders of magnitude higher than those of other layer materials. By using different excitation wavelength, the In2Se3 nanosheets show a higher photoresponse to the infrared light illumination. The environment-dependent photoconductivity measurement indicates that the In2Se3 nanosheets follow the oxygen-sensitized photoconduction mechanism. The physical origins resulting in the superior photoconductivity and detector performance in the In2Se3 nanosheets were also discussed.

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