Study On The Properties Of ?-Ga₂O₃ Based MESFET And UV Detector By Mechanical Stripping

As a sort of new semiconductor material,gallium oxide??-Ga₂O₃?has the advantages of ultra-wide band gap,high breakdown electric field,good thermal stability and chemical stability,and is a promising semiconductor material.It has wide application prospects in solar blind UV detector,gas sensor,photocatalyst and high-power electronic device.In this paper,two kinds of devices,metal-semiconductor field effect transistor?MESFET?and solar blind UV detectors were prepared based on the single crystal ?-Ga₂O₃ microbelts by mechanical stripping.The electrical and photoelectric characteristics of the two devices were studied.The main results of the paper are as follows:?1?The metal-semiconductor field effect transistors were prepared based on the single crystal ?-Ga₂O₃ microbelts by mechanical stripping.When the gate length of the device was 1mm and the spacing between the source and drain electrodes was 4 mm,the effects of different microbelt widths on the output and transfer characteristics of the devices are studied.It was found that the different microbelts widths has a significant effect on the electrical characteristics of the device.With the increasing microbelts widths,the saturation drain current and the transconductance of the devices are also enhanced.When the drain voltage is 15 V,the saturation drain current of the ?-Ga₂O₃ microbelts with a width of 160 ?m was 4.4 times higher than that of the ?-Ga₂O₃ microbelts with a width of 40 ?m,and the transconductance was 3.8 times.Furthermore,breakdown voltage of device was over 200 V.?2?The solar blind UV detectors were prepared based on the single crystal ?-Ga₂O₃ microbelts by mechanical stripping.The photoelectric test shows that the detector has a strong sensitivity to 254 nm UV light,and the device has a very low dark current of 9.89×10-3 n A.When the length and width of the ?-Ga₂O₃ microbelts are 2.5 mm and 100 ?m respectively,the response time and recovery time of the device are about 2.47 s and 1.06 s,respectively,and the ratio of light to dark current reached 4×103 at a bias of 5 V,indicating that detector has excellent photoelectric performance.Moreover,the influence of different ?-Ga₂O₃ microbelts width on the devices performance was also studied.When the width of ?-Ga₂O₃ microbelts were 70 ?m,80 ?m and 100 ?m,respectively,the photocurrent value of the device are 9.8 n A,17.5 n A and 40 n A,respectively under 5 V bias,and the responsivity were 1.12 A/W,1.74 A/W and 3.2 A/W,respectively.