DIRECT OBSERVATION OF MINIBAND-EDGE SINGULARITIES IN THE OPTICAL-SPECTRA OF GAAS/ALAS SUPERLATTICES

Article

关键词: STARK LOCALIZATION;    ELECTRIC-FIELD;    DISPERSION;    EXCITONS;    STATES;   

DOI  :  10.1103/PhysRevB.49.1809

来源: SCIE

【 摘 要 】

Band-edge optical transitions in GaAs/AlAs superlattices with different miniband widths are investigated by low-temperature-photocurrent, photoluminescence-excitation, and reflectance spectroscopy. Direct spectroscopic evidence is given for excitonic effects at saddle-type critical points which are related to M(1) Van Hove singularities at the upper miniband edges, for both heavy-hole and light-hole excitons. Excellent agreement is obtained between the observed transition energies and the miniband widths deduced from Kronig-Penney model calculations.

【 授权许可】

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