Localized and extended exciton states in narrow GaAs/AlGaAs quantum wells

I. Brener; E. Cohen; Arza Ron; L. Pfeiffer

doi:10.1016/0749-6036(89)90288-7

Localized and extended exciton states in narrow GaAs/AlGaAs quantum wells

I. Brener, E. Cohen, Arza Ron, L. Pfeiffer

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7 Scopus citations

Abstract

We report on the selective excitation of photoluminescence (PL) and resonant Raman scattering (RRS) study of two multi-quantum well (MQW) structures at T=2K. Both structures consist of 10 GaAs wells separated by 200 Å of Al_0.28Ga_0.72As barriers grown by MBE. One MQW was grown in an uninterrupted growth process while the other was grown with 40 seconds interruption at each of the interfaces. Both samples show inhomogeneously broadened luminescence bands, with a characteristic splitting due to "interface islands" in the interrupted growth sample. Selective excitation into its low energy tail reveals spectral diffusion indicative of localized excitons. The RRS by LO phonons shows an enhancement of the scattering efficiency at the outgoing beam which is 20-fold stronger than that of the incoming one. The peak energy and band width of the RRS profile reflect the extended excitons density of states. This is interpreted in terms of resonance enhancement by exciton scattering by interface potential fluctuations.

Original language	English (US)
Pages (from-to)	223-226
Number of pages	4
Journal	Superlattices and Microstructures
Volume	5
Issue number	2
DOIs	https://doi.org/10.1016/0749-6036(89)90288-7
State	Published - 1989
Externally published	Yes

All Science Journal Classification (ASJC) codes

General Materials Science
Condensed Matter Physics
Electrical and Electronic Engineering

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10.1016/0749-6036(89)90288-7

Cite this

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title = "Localized and extended exciton states in narrow GaAs/AlGaAs quantum wells",

abstract = "We report on the selective excitation of photoluminescence (PL) and resonant Raman scattering (RRS) study of two multi-quantum well (MQW) structures at T=2K. Both structures consist of 10 GaAs wells separated by 200 {\AA} of Al0.28Ga0.72As barriers grown by MBE. One MQW was grown in an uninterrupted growth process while the other was grown with 40 seconds interruption at each of the interfaces. Both samples show inhomogeneously broadened luminescence bands, with a characteristic splitting due to {"}interface islands{"} in the interrupted growth sample. Selective excitation into its low energy tail reveals spectral diffusion indicative of localized excitons. The RRS by LO phonons shows an enhancement of the scattering efficiency at the outgoing beam which is 20-fold stronger than that of the incoming one. The peak energy and band width of the RRS profile reflect the extended excitons density of states. This is interpreted in terms of resonance enhancement by exciton scattering by interface potential fluctuations.",

author = "I. Brener and E. Cohen and Arza Ron and L. Pfeiffer",

year = "1989",

doi = "10.1016/0749-6036(89)90288-7",

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TY - JOUR

T1 - Localized and extended exciton states in narrow GaAs/AlGaAs quantum wells

AU - Brener, I.

AU - Cohen, E.

AU - Ron, Arza

AU - Pfeiffer, L.

PY - 1989

Y1 - 1989

N2 - We report on the selective excitation of photoluminescence (PL) and resonant Raman scattering (RRS) study of two multi-quantum well (MQW) structures at T=2K. Both structures consist of 10 GaAs wells separated by 200 Å of Al0.28Ga0.72As barriers grown by MBE. One MQW was grown in an uninterrupted growth process while the other was grown with 40 seconds interruption at each of the interfaces. Both samples show inhomogeneously broadened luminescence bands, with a characteristic splitting due to "interface islands" in the interrupted growth sample. Selective excitation into its low energy tail reveals spectral diffusion indicative of localized excitons. The RRS by LO phonons shows an enhancement of the scattering efficiency at the outgoing beam which is 20-fold stronger than that of the incoming one. The peak energy and band width of the RRS profile reflect the extended excitons density of states. This is interpreted in terms of resonance enhancement by exciton scattering by interface potential fluctuations.

AB - We report on the selective excitation of photoluminescence (PL) and resonant Raman scattering (RRS) study of two multi-quantum well (MQW) structures at T=2K. Both structures consist of 10 GaAs wells separated by 200 Å of Al0.28Ga0.72As barriers grown by MBE. One MQW was grown in an uninterrupted growth process while the other was grown with 40 seconds interruption at each of the interfaces. Both samples show inhomogeneously broadened luminescence bands, with a characteristic splitting due to "interface islands" in the interrupted growth sample. Selective excitation into its low energy tail reveals spectral diffusion indicative of localized excitons. The RRS by LO phonons shows an enhancement of the scattering efficiency at the outgoing beam which is 20-fold stronger than that of the incoming one. The peak energy and band width of the RRS profile reflect the extended excitons density of states. This is interpreted in terms of resonance enhancement by exciton scattering by interface potential fluctuations.

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DO - 10.1016/0749-6036(89)90288-7

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JO - Superlattices and Microstructures

JF - Superlattices and Microstructures

IS - 2

ER -

Localized and extended exciton states in narrow GaAs/AlGaAs quantum wells

Abstract

All Science Journal Classification (ASJC) codes

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