| Monoclinic ?-Ga2O3 is an ultra-wide bandgap energy(4.9eV)semiconductor material,which has been regarded as a promising material for next-generation power electronic devices and optoelectronic devices.The ?-Ga2O3 is an ideal material for solar blind detector because its optical response peak located at the center of the solar blind ultraviolet band without composition modulation.The ?-Ga2O3 micro/nano structures has large surface volume ratio and good crystal quality,which can significantly increase the sensitivity of the photodetector.In this paper,according to the present research hotspots and difficulties on ?-Ga2O3,high-density,large-scale centimeter-level ?-Ga2O3 microwires were grown by CVD method.The solar-blind UV photodetector based on a single ?-Ga2O3 microwire was fabricated,and the photoelectric characteristics of the detector were studied.The main research contents of the thesis are as follows:(1)The large-scale and centimeter-level ?-Ga2O3 microwire with range in length from 0.2 to 1cm were grown by chemical vapor deposition method without any catalyst.The effect of the growth temperature on the morphology,structure and optical properties of ?-Ga2O3 was investigated.The results show that the growth temperature has a great influence on the length and quality of the microwire.With the increasing growth temperature,the length of ?-Ga2O3 microwire becomes longer and the crystal quality becomes better.When the growth temperature increases to 1150?,the length of the microwire reaches its maximum,and then with the further increase of temperature,the length and quality of the microwire become shorter and worse.It is concluded that the optimum growth temperature is 1150?.Furthermore,the optical properties of ?-Ga2O3 microwire are studied.(2)The MSM structured photodetector based on single ?-Ga2O3 microwire has been fabricated.The photodetector exhibited a low dark current of 1.10nA,and the current increases rapidly to 5.12?A and the ratio of light to dark current is about 4.65×103 under 254 nm UV light with a 10V bias voltage.In addition,the photodetector operated at a bias voltage of 10V can achieve excellent comprehensive photo-detection properties for 254nm ultraviolet light:the responsivity and quantum efficiency are high as 17.06A/W and 8329%,respectively,along with short response time and recovery time of 0.34s and 0.25s.In addition,the optical response of the device was enhanced by coating the surface of the microwire with Au nanoparticles. |
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