Study Of The Optoelectronic Properties Of SiO₂ Crystals Based On The Doping Of C And Ti Atoms

SiO₂ crystal has the advantages of simple preparation,adjustable particle size,high compatibility,etc.It has become a key basic raw material for many cutting-edge fields such as electronic information industry,intelligent manufacturing equipment,solar energy and energy efficiency,etc.It is receiving more and more attention,especially in the fields of photoelectric sensors,optical information processing and storage devices,optical communications and lasers have a broad prospect.As one of the popular application materials,the photoelectric properties of SiO₂ crystals are not only susceptible to the influence of external environment such as temperature and pressure,but also highly susceptible to the influence of other material materials,such as inevitable residual Ti⁴⁺,Al³⁺and other impurities during the production process,as well as the use of C,Yb and other atomic doping in the practical application process to achieve enhanced performance of photoelectric materials.Therefore,it is particularly important to investigate the effect of relevant atomic doping on the optoelectronic properties of SiO₂ crystals,both from the point of view of SiO₂crystal purification and for extended applications.In this paper,the cell structures of C-doped and Ti-dopedα-SiO₂,β-SiO₂ and Stishovite were constructed and geometrically optimised by applying the CASTEP module in Material Studio software.The stability of the cell structures was determined by calculating the variation of energy with lattice constant and binding energy,and the energy level structure,density of states and reflection and absorption properties,refractive index and extinction coefficient,dielectric constant and Raman spectral properties of the six crystals after doping were calculated respectively.It was found that the band gap of Stishovite decreased from 5.169 e V to 1.786 e V after C-doping,and Stishovite was transformed from an insulator to a P-type semiconductor material with an increase in band gap of 0.579 e V and 0.337 e V forα-SiO₂ andβ-SiO₂ crystals,respectively;Ti doping reduces the band gap of all three crystals and transforms them into P-type semiconductor materials,with the most pronounced change in conductivity in Stishovite.C doping enhances the reflectance and absorption ofα-SiO₂ andβ-SiO₂ in the energy range of 10 e V-25 e V,while the refractive index and extinction coefficient do not change significantly,while the reflectance,absorption,refractive index and extinction coefficient of Stishovite are enhanced in the low energy range below 5 e V;the reflectance,absorption,refractive index and extinction coefficient of the three crystals are enhanced in the low energy range below 10 e V and the high energy range of 35 e V after Ti doping.The analysis of the dielectric constants shows that C doping enhances the electrical energy storage capacity and electrical energy dissipation of Stishovite at low energies;Ti doping increases the electrical energy storage capacity of the three crystals,especially Stishovite,at low energies and enhances the electrical energy dissipation of Stishovite at high energies.At different temperatures and pressures,the number of Raman lines ofα-SiO₂ andβ-SiO₂ increases after C doping,and the energy intensity of Raman lines of Stishovite increases significantly around the frequency of 1000cm^-1;the number of Raman lines of all three crystals decreases after Ti doping,and the intensity of Raman lines ofα-SiO₂ andβ-SiO₂ increases around the frequency of1100 cm^-1,while the intensity of Raman lines of Stishovite increases less than that of C doping.The enhancement of the intensity is less than that of the C doping.In conclusion,the research in this paper broadens the application of SiO₂crystals and provides more theoretical support for subsequent experiments.