Fabrication Of InAs Nanowire Arrays And Investigation Of Its Photosensitive Properties

InAs material is the representative of third-generation semiconductor material and considered as the building blocks for future optoelectronic devices,which has attracted much attention in recent years.InAs is an important narrow direct-band gap semiconductor material with high electron mobility,high luminous efficiency and stable chemical properties at room temperature.Based on these excellent properties,many InAs based photodetectors,field-effect transistors,lasers and gas detectors have been the hotspot of current research.In addition,it have been reported that the InP shell can significantly improve the electrical and optical properties of InAs material,however,the photosensitive characteristics of InAs/InP heterojunction nanowires are still lacked.In this paper,we growed InAs/InP heterojunction nanowires with self-assembled MOCVD equipment.The thickness of InP shell was 0 nm,1.1 nm,3.3 nm,6.5 nm and 18 nm respectively.With the method of dielectrophoresis combined with surface microgroove,a fixed number of InAs/InP nanowires were aligned and fabricated field-effect transistors by semicond uctor technology.Finally,we designed testing circuit and fabricated photosensitivity testing system,successfully investigated the effects of InP shell thickness and gate voltage on the photoresponse properties of InAs/InP core/shell NW.The experiment results show that the InAs/InP heterojunction nanowire transistor has the best photoresponse with gate voltage of 0 V and an InP thickness of 3.3 nm.The sensitivity and response speed of the transistor device gradually increased with the increased InP shell thickness.When the InP layer thickness reached 3.3 nm,the device sensitivity and response speed reached the maximum.Related photoresponse mechanism can be explained via p/n-type transport behavior,radial build-in electric field as well as trapping of the electrons at InAs/InP dislocation interface.