| MgxZn1-xO ternary alloy material can be realized by adjusting the size of the Mg component in the material to achieve the band gap from 3.37eV-7.8eV adjustable.At the same time,because of its matching single crystal substrate?ZnO and MgO?and the advantage which other wide band gap semiconductors had.It has become one of the most popular materials for the preparation of UV photodetectors.At the same time,it is located in the solar blind ultraviolet UVC band?220nm<l<280nm?due to its high concentration of magnesium?x>0.5%?.Therefore,it has high research value and application prospect in the field of solar blind ultraviolet photodetectors.But how to effectively inhibit the phase separation and improve the electrical properties of thin films became the key to the study.In this paper,MgZnO:Ga doped Ga film material is used to improve the high resistivity problem and the coexistence of phase splitting or single phase polycrystal orientation in high magnesium component.The main contents of this thesis are as follows:First of all,in this paper,the preparation parameters of MgZn O:Ga thin film were optimized: the method of using RF magnetron sputtering on the quartz substrate,by fixing the other parameters were changed,sputtering pressure,sputtering power,argon oxygen ratio and annealing temperature were prepared by four groups of films.By X ray diffraction?XRD?,X ray photoelectron spectroscopy?XPS?,atomic force scanning?AFM?,scanning electron microscopy?SEM?,UV-Vis spectroscopy and Holzer effect testing of thin films,the results show that MgZnO:Ga thin films grown only a single cubic phase?111?orientation,through the crystal quality of the films were analyzed.The surface morphology,electrical and optical properties,get the preparation parameters of thin films for the best: the sputtering pressure is 0.5Pa,the sputtering power is 100 W,the oxygen argon ratio is 8:32,the annealing temperature was 500°C.Secondly,Secondly,the MgZnO thin films without Ga were grown under the same sputtering parameters,MgZnO:Ga films by comparing the Ga prepared by Ga doping is conducive to the promotion of a single cubic phase formation,and the?111?direction orientation;At the same time,the carrier concentration and electron mobility of the films can be increased.And it is found that the optical transmission edge of the film can be shifted blue.The analysis results show that this effect is mainly due to the increase of Mg component in the film and the Burstein-Moss effect caused by doping.Furthermore,the buffer layer?ZnO and CuO?influence on the growth of MgZnO:Ga films,we found that the different crystal orientation of MgZnO:Ga thin films grown on different buffer layers on the transmission and emission spectra,and found that the films are red shift;Then this paper explores the effects of Ga doping and CuO buffer layer on MgZnO photoconductive device,and the device of I-V voltammetry,found that the device under illumination,the electrical conductivity was increased;spectral response test found that the device appeared at 220 nm peak response of the device,when the applied voltage is 10 V,the degree of response at 1.09×10-2 A/W,The cut-off edge is located at 230 nm,indicating that the photoconductive device has the capability to detect the deep ultraviolet UVC band.It is also found that both the Ga doping and the growth of the CuO buffer layer can improve the responsivity of the device.Moreover,the p-n structured films of p-CuO/n-MgZnO:Ga were grown on quartz substrates by magnetron sputtering,in the dark conditions were I-V curve test,found the rectification effect is obvious,the potential to be used as a MgZnO:Ga based photovoltaic probe material is demonstrated.Finally,the paper also tried to use N2 as a nitrogen source by changing the ratio of nitrogen and argon to make the P type MgZnO:Ga material,but the results are not ideal,so the film appears N type conductivity type mechanism is analyzed,the reason is N2 as nitrogen source will also introduce N doped?N?o acceptor defects and?N2?o donor type defects,the plus sign of donor type defects in the Zni film,the kinds of defect interactions,the P doped films fail to show N type conductive type. |
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