Theoretical Investigation Of Nonlinear Optical Properties Of Doped Beryllium Nanowires

In recent years,a great variety of nonlinear optics(NLO)materials have been widely used in optical communication,information processing,optical storage and other fields,which makes the research on the properties of nonlinear optical materials become a hot topic.It is particularly important to develop and design high-performance nonlinear optical materials.Previous studies have shown that the introduction of extra electrons into the system to enhance its first hyperpolarizability is a favored way.The representative one is doping alkali metal atoms into different types of organic complexants to design a large number of electride molecules.These NLO electride molecules have larger first hyperpolarizability values,but their thermostabilities are unsatisfactory since the organic complexants are not heat resistant enough.In order to enhance the stability of NLO electride molecules,our group proposed the new concept of“all-metal electride”.In this paper,doped beryllium nanowire Ca²⁺(Be₆)_n^4-Mg²⁺(n=1-7)have been successfully constructed.This study has found that as a special all-metal charge transfer salts,beryllium nanowires Ca²⁺(Be₆)_n^4-Mg²⁺have great nonlinear optics(NLO)effect(₀⁰)=1.05×10⁴-1.12×10⁵ au),which can be attributed to the doping of Ca and Mg atoms.It is worth noting that the₀⁰)value increases rapidly with the increase of the number of Be₆ octahedron units(n),indicating that the length of nanowire has a significant effect on its NLO response.At the same time,these NLO nanowires possess working wavebands in the infrared(IR,>2800 nm)and ultraviolet(UV,<200 nm)regions,and hence,can be used as new infrared and ultraviolet NLO materials.In addition,this work also reveals that the doped beryllium nanowires Ca²⁺(Be₆)_n^4-Mg²⁺(n=1-7)have strong Janus electride properties(electron-donating and electron-withdrawing properties).In summary,a batch of new metal nanowires which can be used in the fields of infrared and ultraviolet nonlinear optical materials and electronic devices have been successfully predicted.