Theoretical Study On Electronic Structures And Optical Properties Of Doped GaN

Recently,due to the broad-band gap semiconductor materials has potential application value and arouse people's attention in high frequency components,short wavelength light emitting diobe,laser and ultraviolet detector.Among them,gallium nitride(GaN)luminous material has many advantages for example,wide forbidden band,high electronic drift speed,corrosion resistance and high temperature resistance,etc.and it is widely used in purple and blue band.GaN light emitting diode with low power consumption,small volum,long life shows great application value.Doping is an effective method to improve the properties of semiconductor materials,which is widely used in the research and manufacture of semiconductor materials.We studied the ideal GaN and GaN doped with Zn,Ti,Se,Ti-Se by first principle density functional theory(DFT)method with the generalized gradient approximation(GGA),and the electronic structure and optical properties.Firstly,we introduced the GaN material physical properties,research progress and the first principle of the basic theoretical basis.We optimized the structural of the computational system and we get lattice constant accord with experiment values well,so that to ensure the rationality of the calculation.Then,the effects of Zn,Ti,Se and Ti-Se doping on the electronic structure and optical properties of GaN,GaN(110)crystal plane were calculated,the results of calculation are analyzed.Based on the analysis of the calculated results,the following conclusions can be drawn: Firstly,the lattice of the doped crystal structure is distorted to a certain extent,and the lattice constant increases,especially the incorporation of Se has a great influence on the crystal structure,which leads to a high degree of distortion.Secondly,two kinds of structure of band width in doping decreased to a certain extent,the decreasing degree is mainly determined by the impurity level and the introduction of hybrid orbital effect caused by the decrease of the band gap,enhance the ability of electronic transition.Finally,by doping can make material optical properties change,doping material and doping surface materials exhibit different optical absorption behavior,especially the co-doping case is more obvious,has certain reference value for the research and application of materials.