Research On Graphene/?-? Group Nanowire Schottky Junction Photoelectric Conversion Device

?-? semiconductor nanowires have become a research focus in the field of nano-optoelectronics in recent years due to their quasi-one-dimensional structural characteristics and novel optoelectronic properties.As an emerging two-dimensional material,graphene has excellent properties such as high electron mobility,high electrical conductivity,and high light transmission,and has shown unique advantages in the field of high-speed electronic devices and photoelectric detection.The combination of ?-? nanowires and graphene with two low-dimensional structures is expected to give full play to their advantages and realize new nano optoelectronic devices with higher response and faster rates.In this paper,the working principle,preparation process and optoelectronic characteristics of graphene/?-? nanowire Schottky junction photoelectric conversion devices are studied in depth.The main work and innovations are as follows:(1)Explored ?-? nanowire growth,single-layer graphene transfer,and graphene/?-? nanowire Schottky junction processes,and Schottky junctions of graphene/single InP nanowires and graphene/single InAs nanowires were prepared respectively,and the Schottky barrier heights were 0.49 eV and 0.18 eV,respectively.(2)A graphene/InP nanowire Schottky junction photodetector was prepared and tested.The device is an ohmic contact at one end and a Schottky contact at one end,which shows obvious rectification characteristics.Under the wavelength of 532 nm and power density of 56.2 W/cm2,the device has a responsivity of 5.2 A/W and a response speed of 2 ?s/2.5 ?s at a bias voltage of 0.5 V,which is 3 orders of magnitude faster than an ohmic contact photodetector,and shows important application potential in the field of high-speed photoelectric detection.(3)A graphene/InAs nanowire Schottky junction photodetector was prepared and tested.Under the Schottky junction's forward biased state,the device is dominated by the light-induced gate control effect of InAs nanowires and exhibits a negative light-guiding characteristic.The responsivity is 1.4×103 A/W and the response speed is 20 ms/25 ms under a bias voltage of 1V and a light intensity of 0.031 W/cm2;Under the reverse bias state of the Schottky junction,the device exhibits positive light guide characteristics.The response is 5.62×103 A/W at the same light intensity,and the response speed is 1 ?s/5 ?s.It has important application prospects in high-speed nano photodetectors.