富砷GaAs(001)-(2×4)重构表面光电发射性质  

Study on the photoemission properties of As-rich GaAs(001)-(2×4)reconstructed surface

作　　者：鱼晓华 金祖德 YU Xiaohua;JIN Zude(Department of Physics and Electronic Engineering,Yuncheng University,Yuncheng 044000,China)

机构地区：[1]运城学院物理与电子工程系,山西运城044000

出　　处：《扬州大学学报（自然科学版）》2022年第1期25-31,共7页Journal of Yangzhou University：Natural Science Edition

基　　金：湖北省自然科学基金资助项目(2017CFB332);山西省高等学校科技创新资助项目(2019L0871)。

摘　　要：采用密度泛函理论计算了5种GaAs(001)-(2×4)重构表面的电子结构与光学性质,比较了不同GaAs(001)-(2×4)重构表面的表面能与功函数,分析了重构表面的能带结构和态密度.结果表明:β_(2)(2×4)重构表面最稳定,具有最小的功函数;重构表面处的电子向材料体内运动从而形成表面能带弯曲区;材料通过改变表面电子分布平衡偶极子产生的电势,从而消除偶极矩使表面稳定.最后分析比较了5种重构表面的吸收谱和反射谱,发现重构表面吸收系数与反射率小于体材料,透过率大于体材料,有利于光子透过表面从而激发体内电子.The electronic structure and optical properties of 5 type GaAs(001)-(2×4)reconstructed phases have been calculated by using the density function theory.The surface energy,work function,band structure and density of state of reconstruction phases are analyzed and compared.Calculation results indicate thatβ_(2)(2×4)is the most stable reconstruction phase and owns the lowest work function.The electrons at reconstruction surfaces move into bulk,forming the band bending region.The surface electron distribution is changed to balance the potential generated by the dipoles,therefore the dipole moment is eliminated to stabilize the surface.Finally,The absorption coefficient and reflectivity of these reconstruction phases are compared,results show that absorption coefficient and reflectivity at surface are lower than those of the bulk,transmittance at the surface is larger than bulk material,which is beneficial to the photons to move through the surface to excite electron.

关 键 词：GAAS 重构表面 表面能 态密度 光学性质 

分 类 号：TN304.2[电子电信—物理电子学]