Study On Photoelectrocatalysis And Photodetection Performance Of 4H-SiC Nanoarray

SiC is a typical third generation semiconductor with many excellent properties,especially outstanding stability,which gives it a significant advantage in the development of optoelectronic devices in service under demanding conditions.SiC low-dimensional nanomaterials have the excellent characteristics of SiC and also have the unique advantages of nanomaterials,which provides a great possibility for the development of optoelectronic devices with excellent performance and high efficiency.In this paper,4H-SiC nanoarrays were prepared by anodic oxidation of 4H-SiC single wafers,and fine morphology control of 4H-SiC nanoarrays was achieved.On this basis,the applications of 4H-SiC nanoarrays in the fields of photocatalysis and photodetection were explored,it provides the possibility for the further application of SiC in the field of optoelectronic devices.Based on the work of this thesis,the following research results have been obtained:(1)4H-SiC nanoarrays were prepared by anodization,and the effects of surfactants,electrolyte temperature,hydrochloric acid,and pulse duty ratio on the morphology of 4H-SiC nanoarrays were investigated.The morphology of nanobelts and nanorods,etc.,achieves fine control of the morphology of the nanoarray,which greatly enriches the morphology of the SiC nanoarray.(2)A two-step anodic oxidation method was designed to prepare an integrated 4H-SiC nanoarray photoanode.The photoanode can be directly tested for photocatalytic performance,and the influence of the morphology of 4H-SiC nanoarray on its photocatalytic performance was explored.The results showed that the photocurrent density of the photoanode in 1 mol/L Na₂SO₄ solution under 1.23 V(vs RHE)bias was up to 3.21 m A cm^-2 when the nanoarray was in the shape of broken holes,which was at the leading level in SiC materials.(3)The wide-temperature photocatalytic performance of 4H-SiC integrated nanoarray photoanode was investigated,and it was found that its photocurrent density could reach 2.17m A cm^-2 in the electrolyte at 45?,indicating that the 4H-SiC integrated nanometer array photoanode has great application potential in wide temperature photoelectrocatalyst.(4)A thermal evaporation device was used to deposit a silver interdigitated electrode on the 4H-SiC nanoarray film to construct a photodetector.The photodetection performance was tested using a semiconductor characterization system,the results showed that when the voltage is 2 V the photocurrent and dark current ratio reaches 42,it shows that 4H-SiC nanoarray has a great potential for application in the field of photodetector.