The photoconductivity of single-crystalline selenium nanotubes (SCSNTs) under a range of illumination intensities of a 633 nm laser is examined using a novel two-terminal device arrangement at room temperature. It is found that SCSNTs forms Schottky barriers with W and Au contacts, and the barrier height is a function of the light intensity. In the low-illumination regime below 1.46 x 10~(-4) mu W mu m~(-2), the Au-Se-W hybrid structure exhibits sharp on/off switching behaviour, and the turn-on voltages decrease with increasing illuminating intensities. In the high-illumination regime above 7 x 10~(-4) mu W mu m~(-2), the device exhibits ohmic conductance with a photoconductivity as high as 0.59 OMEGA cm~(-1), which is significantly higher than the reported values for carbon and GaN nanotubes. This finding suggests that a SCSNT is potentially a good photo-sensor material as well as a very effective solar cell material.
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机译：使用新型的两端子设备在室温下，研究了在633 nm激光照射强度范围内单晶硒纳米管（SCSNT）的光电导性。发现SCSNTs与W和Au接触形成肖特基势垒，势垒高度是光强度的函数。在1.46 x 10〜（-4）mu W mu m〜（-2）以下的低照度条件下，Au-Se-W混合结构表现出尖锐的开/关切换行为，并且开启电压随着增加而降低照明强度。在高于7 x 10〜（-4）mu W mu m〜（-2）的高照明条件下，该器件表现出欧姆电导，光电导率高达0.59 OMEGA cm〜（-1），远高于碳和GaN纳米管的报告值。该发现表明，SCSNT可能是良好的光传感器材料，也是非常有效的太阳能电池材料。
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