GaSe/MoS_(2)垂直范德瓦尔斯异质结构光电探测器性能研究

Study on the Performance of GaSe/MoS_(2) Vertical van der Waals Heterostructure Photodetector

近年来,光电探测器被广泛地应用在成像、传感、光通信、生物技术等领域,人们迫切希望能通过简单的制备方法获得高性能低能耗的光电探测器。本文通过机械剥离的方法制备二维GaSe、MoS_(2)和石墨烯,再通过定向转移的方法实现Au电极/GaSe/MoS_(2)/石墨烯堆叠,成功获得了GaSe/MoS_(2)垂直范德瓦尔斯异质结构光电探测器。在外加电压为2 V时,该光电探测器对450 nm光的响应度为351 mA/W,探测灵敏度为1.18×10^(9)Jones,外量子效率为97%。受GaSe禁带宽度的影响,器件仅对波长小于620 nm的光具有较高的响应度。在外加电压为0 V时,该光电探测器也具有重复探测450 nm光的能力,且响应速度较快,响应时间和恢复时间分别为0.36 s和0.24 s。该光电探测器杰出的性能归功于II型垂直范德瓦尔斯异质结构的形成,表明该异质结构在高性能低功耗光电探测器制作上有巨大的应用潜力。

In recent years,photodetectors have been widely applied to imaging,sensing,optical communication,biotechnology and other fields.It is urgent to fabricate photodetectors with high performance and low energy consumption by a simple preparation method.In this paper,two-dimensional GaSe,MoS_(2)and graphene were prepared by the mechanical exfoliation.Then,the GaSe/MoS_(2)vertical van der Waals heterostructure photodetector was fabricated by transferring GaSe、MoS_(2)and graphene onto the Au electrode in turn.At a bias of 2 V,the photodetector has a responsivity of 351 mA/W to 450 nm light,a detectivity of 1.18×10^(9)Jones,and an external quantum efficiency of 97%.Limited by the band-gap of GaSe,the device has a high responsivity only to the light with wavelength less than 620 nm.At a bias of 0 V,the photodetector also can detect 450 nm light repeatedly,and the response speed is fast.The response time and the recovery time are 0.36 s and 0.24 s,respectively.The outstanding performance of the photodetector is attributed to the type-II vertical van der Waals heterostructure,indicating that the heterostructure has a great potential in the fabrication of high-performance and low-power photodetectors.