压力下纤锌矿氮化物三元混晶中电子-声子相互作用对表面电子态的影响  

Effect of the Electron-Phonon Interaction on Electronic Surface States in Wurtzite Nitride Ternary Mixed Crystals under Pressure

作　　者：李根小[1] 闫祖威[1] LI Genxiao;YAN Zuwei(Collegeof Science,InnerMongolia Agricultural University,Hohhot O1oo18,China)

机构地区：[1]内蒙古农业大学理学院,呼和浩特010018

出　　处：《内蒙古大学学报（自然科学版）》2022年第4期359-367,共9页Journal of Inner Mongolia University：Natural Science Edition

基　　金：国家自然科学基金资助项目(12164033);内蒙古自治区自然科学基金资助项目(2020MS01008)。

摘　　要：考虑电子-表面光学声子相互作用及流体静压力的影响,采用变分法研究了半无限纤锌矿氮化物三元混晶A_(x)B_(1-x)N(A,B=Al, Ga and In)中表面电子态问题。对纤锌矿Al_(x)Ga_(1-x)N,Al_(x)In_(1-x)N和In_(x)Ga_(1-x)N材料,导出了电子-表面光学声子相互作用系统的有效哈密顿量,数值计算了表面电子态能级及其移动量和电子-表面光学声子耦合常数分别随流体静压力和组分的变化关系。结果表明,考虑电子-表面光学声子相互作用后表面电子态能级会下降几十meV。随流体静压力的增加,材料晶格常数和禁带宽度的变化所引起的表面电子态能级的升降博弈导致表面电子态能级随流体静压力的变化比较复杂。而表面电子态能级随组分的变化是单调的。流体静压力下纤锌矿氮化物三元混晶中,电子-表面光学声子相互作用对表面电子态的影响不应被忽略,尤其是对于具有较宽禁带宽度和较强电子-声子耦合的材料。A variational method is proposed to investigate electronic surface states in semi-infinite wurtzite nitride ternary mixed crystals A_(x)B_(1-x)N(A,B=Al, Ga and In),by taking the effects of the electron-Surface-Optical-phonon interaction and hydrostatic pressure into account.The effective Hamiltonian is derived.The numerical computations have been performed for the electronic surface state energy levels, the shifts of the electronic surface state energy level and electron-Surface-Optical-phonon coupling constants as functions of the hydrostatic pressure and the composition for wurtzite Al_(x)Ga_(1-x)N,Al_(x)In_(1-x)N and In_(x)Ga_(1-x),respectively.The results show that the electron-Surface-Optical-phonon interaction lowers the electronic surface state energy levels for dozens of meV.It is indicated that the hydrostatic pressure effect on the electronic surface states energy levels are more complicated.It is due to the competition of change among the lattice constant and the band gap with pressure.The electronic surface states energy levels change monotonously with the composition.The effect of electron-Surface-Optical-phonon interaction on the electronic surface states in wurtzite nitride ternary mixed crystals under hydrostatic pressure can not be neglected, in specially, for the materials with wider band gaps and a stronger electron-phonon coupling.

关 键 词：表面电子态 电子-表面光学声子相互作用 流体静压力 纤锌矿氮化物三元混晶 

分 类 号：O471.3[理学—半导体物理]