Study On The Deep Ultraviolet Sensitive Properties Of Boron Nitride Nano-Film

Ultraviolet radiation means a sort of electromagnetic radiation.And it has a wavelength from 10 to 400 nm.Ultraviolet radiation is made up of the following areas:UVA:320-400 nm,UVB:280 to 320 nm,UVC:100 to 280 nm,and extreme ultraviolet(EUV):10 to 120 nm.However,since the atmosphere and the ozone layer absorb most of the ultraviolet radiation in the UVB,UVC,and UVE regions,deep ultraviolet radiation with a wavelength of less than 280 nm can not reach the surface of the atmosphere.Therefore,the area with a wavelength from 200 to 280 nm is usually called a solar blind zone.At the same time,in the past few decades,the rapid development of the semiconductor industry has benefited deep ultraviolet detection and has been widely used in various research fields.The wide-gap semiconductor materials that have been widely used in deep ultraviolet detection mainly include:Ga₂O₃,Mg_xZn_1-xO,Al N,diamond,etc.,and deep ultraviolet detection based on B N materials is relatively rare.Compared with other semiconductors,BN nanomaterials have a larger band gap,about 5-6 e V,and are ultra-wide band gap semiconductors.Therefore,a lower detection line can be achieved.In addition,boron nitride nanotubes(BNNT)are not easily oxidized,and have good chemical stability,high temperature stability,and mechanical properties,making them a very promising material for deep ultraviolet detection.BNNT with better quality was prepared by mechanical ball milling-assisted annealing method,and the film was formed by spraying,direct peeling,and s uction filtration respectively.Through experiments,it is known that the direct peeling method is the simplest and easy to combine with the substrate.The simulation of the energy band characteristics of BNNT was completed using Material Studio software.The simulation results proved that BNNT is a good ultraviolet absorbing material,and its band gap corresponds to the deep ultraviolet band.The UV-Vis absorption spectrum also proves this well.The production of the mask is completed by laser processing technology,and the growth of the interdigital electrode is completed by magnetron sputtering coating equipment.Finally,the MSM(metal-semiconductor-metal)structured deep ultraviolet photodetector based on BN nanomaterials is successfully prepared.Through testing,it is founded that a suitable metal electrode thickness is 504(?).In addition,the Au/Ni composite material was used as the electrode material,and the detection performance of the device was compared with Au as the electrode respectively,and it was found that the response characteristic of Au/Ni was stronger than that of Au.At the same time,the detector which Au/Ni as the electrode was annealed,with the purpose of further improving the detection performance.By testing,we knew that when the annealing temperature is 500?,the response characteristics of detector would be improved a lot.The most notable is the dark current was reduced to 3.227 p A,the switching ratio increased from 381 times before annealing to 887 times,and the responsivity also increased to 2.863?A/W.