The Study On Electronic And Optical Properties Of In-doped Zinc Blende GaAs

?-? compound semiconductor has very favourable electro-optical properties, excellent mechanical properties and specific band gap ranges, so it has fairly broad applicate prospects in certain areas such as high temperature, high power, highly frequent electronic devices,opto-electronic devices and some special semiconductor devices.The electro-optical properties of In-doped GaAs have been studied by density functional theories based on first-principles in this paper. The roles of different doping proportions and different positions in same proportions to properties of GaAs have been analyzed emphatically in terms of band structure, electron density of states, various optical properties ?complex dielectric function, light refractive rate and reflectivity rate, light absorption coefficient,extinction coefficient and energy loss?. Furtherly, we analyse the characteristics of zinc blende structure-InAs doped Ga, The results are concluded as follows:1.The specific properities of InxGa1-xAs?x=3.125%, 6.25%, 9.375%, 12.5%?have been studied by first-principles calculations. The calculation results indicate that the band gap width of materials is reduced due to the existence of the impurity level, but with the increase of doping proportions, the degree of hybridization of outer electrons of In and As is increased, the band gap width of materials is increased;In terms of optical properties,doped materials absorption edge occur obvious redshift compared with intrinsic GaAs, the doping proportions affect nature of different crystallographic orientations and represent anisotropy,the variational peaks of real part and imaginary part of dielectric function of materials all appear in different crystallographic orientations; With the increase of doping proportions, the static dielectric constant of materials is decreased;doped materials to the electromagnetic wave reflection are relatively weak to the reflection of electromagnetic wave and the average value of refractive rate is near the 0.7 in high energy region, showing the characteristics of high transmittance. When the photon energy is 14.9 eV, energy losses all represent an obvious peak.2.Though Comparating and analysing the influence involving with the characteristics of GaAs doped In of different locations , we find that the band structures of doped systems whether in surfaceor indoor all show the semiconduct characteristics of directing band gap , but there are differences in optical properties, including that the system of three In doped indoor represent same optical properties in [0 0 1]?[10 0] and [0 1 0] crystals and the system of three In doped in surface adding with vacuum represent different optical properties in [0 0 1]?[10 0]and [0 1 0] crystals. Among, there are big differences of changeable trend in [0 0 1] crystal and[1 0 0], [0 1 0] crystals .3.Though analysing and discussing the electronic structure and optical properties of In₂₅Ga₇As₃₂ and In₂₆Ga₆As₃₂ materials, we find that the band gap disappeared in In₂₅Ga₇As₃₂ and In26Ga6 As32 structuralmaterials in which In As doped Ga, presenting gold properties; Light absorpted edge is showed obvious red shift, the maximum peak of real part of dielectric function is larger than sphalerite GaAs in which In doping proportions are 3.125%, 6.25%,9.375% 12.5%, respectively.