p型Ge_xSi_(1-x)/Si多量子阱的红外吸收及其分析

INTERSUBBAND ABSORPTION IN p TYPE Ge x Si 1-x /Si MULTIPLE QUANTUM WELLS AND ITS ANALYSIS

通过测量ＧｅＳｉ多量子阱的红外谱，同时观察到了相应于量子阱内重空穴基态ＨＨ０到重空穴激发态ＨＨ１、轻空穴激发态ＬＨ１和自旋分裂带ＳＯ及连续态间的跃迁吸收．测量了ＧｅＳｉ多量子阱探测器的正入射光电流谱，看到了明显的光响应峰．理论计算中计及了轻、重和自旋分裂带间的耦合及能带的非抛物性，并自洽考虑了哈特里势和交换相关势．与实验结果比较，认为带之间的耦合，使子带间的跃迁情况变得复杂。

A theoretical and experimental study of intersubband absorption in p type Ge x Si 1-x /Si multiple quantum wells are presented,the calculations are performed with envelop function approach,with full inclusion of the degeneracy and warping of the three topmost bulk valence bands described by the strain dependent Luttinger Kohn Hamiltonian.The Hartree potential and the exchange correlation interaction are taken into account in a self consistent manner.And finally the absorption spectra is calculated.We contribute some absoptions observed with normal incident unpolarized infra beam to the band mixing of heavy,light and split off bands in Ge x Si 1-x /Si quantum wells.