Distinct photocurrent response of individual GaAs nanowires induced by n-type doping.
Distinct photocurrent response of individual GaAs nanowires induced by n-type doping.
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DOI：
10.1021/nn300962z
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发表时间：
2012-06
期刊：
影响因子：
17.1
通讯作者：
Hui Xia;Zhen-Yu Lu;Tian-xin Li;P. Parkinson;Z. Liao;Fu-hao Liu;W. Lu;Weida Hu;Pingping Chen-Pingping
中科院分区：
文献类型：
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作者：
Hui Xia;Zhen-Yu Lu;Tian-xin Li;P. Parkinson;Z. Liao;Fu-hao Liu;W. Lu;Weida Hu;Pingping Chen-Pingping
用导电原子力显微镜研究了GaAs纳米线的光电导特性。线性响应对偏置电压的观察中度n掺杂GaAs线与肖特基接触下照明，而未掺杂的表现出饱和的响应。单根纳米线的载流子寿命可以通过模拟其特征光电行为得到。与光致发光结果一致，少数空穴寿命的显着下降，从几百到亚皮秒由n型掺杂引起的，导致不同的光电导功能。此外，通过与AlGaAs壳纳米线的光电行为比较，估算出2 × 10（17）cm（-3）n掺杂裸纳米线的表面载流子等效复合速率>1 × 10（12）s（-1），比掺杂相关的体效应高近30倍。这项工作表明，在纳米线中的故意掺杂可以改变表面状态的电荷状态，并施加显着影响的半导体纳米结构的电学和光电性能。
The doping-dependent photoconductive properties of individual GaAs nanowires have been studied by conductive atomic force microscopy. Linear responsivity against the bias voltage is observed for moderate n-doped GaAs wires with a Schottky contact under illumination, while that of the undoped ones exhibits a saturated response. The carrier lifetime of a single nanowire can be obtained by simulating the characteristic photoelectric behavior. Consistent with the photoluminescence results, the significant drop of minority hole lifetime, from several hundred to subpicoseconds induced by n-type doping, leads to the distinct photoconductive features. Moreover, by comparing with the photoelectric behavior of AlGaAs shelled nanowires, the equivalent recombination rate of carriers at the surface is assessed to be >1 × 10(12) s(-1) for 2 × 10(17)cm(-3) n-doped bare nanowires, nearly 30 times higher than that of the doping-related bulk effects. This work suggests that intentional doping in nanowires could change the charge status of the surface states and impose significant impact on the electrical and photoelectrical performances of semiconductor nanostructures.