Raman scattering near the ( E sub 0 +. Delta. sub 0 ) resonance from (211)-oriented Ga sub 1 minus x In sub x As/GaAs multiple quantum wells

Journal Article · Wed Jul 15 00:00:00 EDT 1992 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.46.1480· OSTI ID:7201384

Sela, I; Smith, D L ^[1]; Subbanna, S; Kroemer, H ^[2]

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1. Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
2. Department of Electrical and Computer Engineering, University of California at Santa Barbara, Santa Barbara, California 93106 (United States)

We present a Raman-scattering study of (211)-oriented Ga{sub 1{minus}{ital x}}In{sub {ital x}}As/GaAs multiple quantum wells grown by use of molecular-beam epitaxy. Off resonance, the Raman scattering satisfied bulk zinc-blende-structure selection rules. Near the ({ital E}{sub 0}+{Delta}{sub 0}) resonance, there is strong LO-phonon Raman scattering in the {ital Z}{prime}({ital X}{prime},{ital X}{prime}){ital {bar Z}} {prime} configuration, where {ital Z}{prime} refers to the growth axis and {ital X}{prime} is in a ({bar 1}11) direction. LO-phonon Raman scattering is forbidden in this configuration by bulk zinc-blende-structure selection rules and does not occur (or at least is much weaker) in (211)-oriented GaAs substrates near this resonance. This Raman process is due to Froehlich-interaction electron-phonon scattering activated by the strain-generated electric fields that occur in the multiple-quantum-well structure. We measure the resonance profile of this Raman process. The scattering efficiency is found to decrease with increasing laser intensity, because of a screening of the strain-generated fields by photoexcited free carriers. We present an electronic-structure calculation that accounts for the energy position of the resonance profile. Based on the electronic-structure results, we discuss simple models for the shape of the resonance profile. A free-carrier screening calculation accurately describes the observed laser-intensity dependence of the efficiency of this Raman process.

• OSTI ID: 7201384
• Journal Information: Physical Review, B: Condensed Matter; (United States), Vol. 46:3; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
GALLIUM ARSENIDES
RAMAN SPECTRA
INDIUM ARSENIDES
ELECTRON-PHONON COUPLING
ELECTRONIC STRUCTURE
MOLECULAR BEAM EPITAXY
SELECTION RULES
ARSENIC COMPOUNDS
ARSENIDES
COUPLING
EPITAXY
GALLIUM COMPOUNDS
INDIUM COMPOUNDS
PNICTIDES
SPECTRA
360606* - Other Materials- Physical Properties- (1992-)