应变Ge空穴有效质量的各向异性与各向同性

Anisotropy and isotropy of hole effective mass of strained Ge

在利用k·p微扰理论获得应变Ge/Si_(1-x)Ge_x价带E(k)-k关系的基础上,研究得到了(001),(101),(111)面应变Ge/Si_(1-x)Ge_x沿不同晶向及各向同性的价带空穴有效质量.结果显示,应变Ge/Si_(1-x)Ge_x沿各晶向的带边有效质量随应力增大而减小,且沿[010]晶向最小;子带空穴有效质量在应力较大时变化不明显,并且在数值上与带边空穴有效质量相差不大.最后利用各向同性有效质量与文献结果进行比对,验证了结果的正确性.

In this paper, the hole effective mass along arbitrarily k wavevector direction and the hole isotropic effective masses in strained Ge/（001）（101）（111）Sil-xCrex are obtained with in the frame work of k · 19 theory. It is found that the hole effective mass of the top valence band along [010] wave vector decreases obviously with stress increasing and its absolute value is smallest. The hole effective mass of the second valence band tends to gently decrease with stress increasing, and is not significant in magnitude. Compared with the existing isotropic effective quality, the result obtained in this paper is proved to be correct.