FAR-INFRARED SPECTROSCOPY OF MINIBANDS AND CONFINED DONORS IN GAAS/ALXGA1-XAS SUPERLATTICES

被引：81

作者：

HELM, M ^{[1
]}

PEETERS, FM ^{[1
]}

DEROSA, F ^{[1
]}

COLAS, E ^{[1
]}

HARBISON, JP ^{[1
]}

FLOREZ, LT ^{[1
]}

机构：

[1] BELLCORE,RED BANK,NJ 07701

来源：

PHYSICAL REVIEW B | 1991年 / 43卷 / 17期

关键词：

D O I：

10.1103/PhysRevB.43.13983

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

We present a far-infrared-absorption study of electrons in lightly doped GaAs/Al(x)Ga(1-x)As superlattices. A grating coupler enables us to observe transitions that require an electric-field polarization along the superlattice axis. We investigate weakly and strongly coupled superlattices, and demonstrate the difference between intersubband transitions and transitions between extended minibands. The line shape of the interminiband absorption deviates considerably from the predictions of a simple single-particle model. We discuss possible reasons in terms of fluctuations and localization. At low temperatures, the absorption spectra are dominated by donor transitions. The transition from the donor ground state to the pure 2p(z) state, which is associated with the second subband, is observed. In a variational calculation, we compute the four-lowest donor states for a variety of superlattice parameters. Excellent agreement between experiment and theory is achieved.

引用

页码：13983 / 13991

页数：9

共 35 条

[1] SUPER-LATTICE BAND-STRUCTURE IN THE ENVELOPE-FUNCTION APPROXIMATION [J].