Study On The Electronic Structure And Optical Properties Of CdSe_xS_1-x

So far, semiconductor materias have been widely applied because that it has strong nonlinear absorption and three-order nonlinear polarizability.The low dimensional semiconductor materials(quantum dots, quantum wires, quantum well) have been widely concerned, research and application in recent years.In the practical application, the semiconductor laser, quantum wire transistors,the preparation of a solar cell or micro cavity laser etc have been developed.As the semiconductor material, its performance will change completely comparing with the bulk material with the decrease of size. Therefore, it is necessary to study the relevant optical properties for the semiconductor material.CdSeS semiconductor material not only belongs to the low dimensional semiconductor materials, semiconductor and polyatomic molecule.Due to the different components,leading to the matreial’s nature changing in electrical, optical and other aspects.In recent years,There are lots of experim ental researches about the CdSeS synthesis of quantum dots,characterized,luminescence performance and the components in the domestic and overseas.However,There are only few reports about the optical calculation of CdSeS and the analysis of CdSeS optical proerities on electronic srructure.So the research of these microscopic mechanism on optical properties of CdSeS is very necessary.This paper mainly studies the Se and S atoms in CdSeS,when they are proportion is changed,The realationship between electronic structure and optical properties. The main work is as follows:1.First-principles study of the different components CdSeS crystal electronic structure and optical properties.First determine its theoretical model,Then according to the different components of the optimization model, This paper, by using the method based on density functional theory pseudopotential plane wave of different components of CdSeS electronic structure,state density, refractive index,the reflection spectrum, absorption spectrum and photoelectric to rate and the calculation of energy loss function system, Provide important theoretical reference for further design and application materials.2.Using Castep model and DOML model in the program with PBE based group of different components(CdSeXS1- X) n(n = 4) clusters through the calculation of the electronic structure and optical properties.Also got the band gap,symmetry,electron density and thermodynamic information.