Zhang Xutao, Yao Xiaomei, Li Ziyuan, Zhou Chen, Yuan Xiaoming, Tang Zhou, Hu Weida, Gan Xuetao, Zou Jin, Chen Pingping, Lu Wei
School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an, Shaanxi 710129, China.
State Key Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, 500 Yutian Road, Shanghai 200083, China.
J Phys Chem Lett. 2020 Aug 6;11(15):6413-6419. doi: 10.1021/acs.jpclett.0c01879. Epub 2020 Jul 27.
We report a high-performance InAs nanowire phototransistor with the photoresponse mechanism governed by the gate-controlled surface states. Detailed characterizations suggest that the high density of surface defect states of the InAs nanowire can capture electrons from the nanowire core to form negative surface charge centers. Before and after light illumination, nanowire surface states undergo processes of capturing and neutralizing the electrons, respectively. This leads to an increase in the concentration and mobility of electrons after light illumination, which endows the device with remarkable photoresponsivity. After modulating the surface states through gate voltage and surface passivation, significantly high responsivity of up to 4.4 × 10 A/W and gain of up to 2.7 × 10 under the illumination of light at the wavelength of 2000 nm are obtained, putting our devices among the high-performance short-wave infrared nanowire photodetectors. This work provides an important reference for understanding the surface effects of nanomaterials and enhancing the performance of nanophotodetectors by modulating the surface states.
我们报道了一种高性能的 InAs 纳米线光电晶体管，其光响应机制由栅极控制的表面态决定。详细表征表明，InAs 纳米线的高密度表面缺陷态能够从纳米线核心捕获电子，形成负表面电荷中心。在光照前后，纳米线表面态分别经历捕获和中和电子的过程。这导致光照后电子浓度和迁移率增加，赋予该器件显著的光响应性。通过栅极电压和表面钝化调制表面态后，在波长为 2000 nm 的光照下，获得了高达 4.4×10 A/W 的显著高响应度和高达 2.7×10 的增益，使我们的器件跻身于高性能短波红外纳米线光电探测器之列。这项工作为理解纳米材料的表面效应以及通过调制表面态提高纳米光电探测器的性能提供了重要参考。
