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Main Author:	I. F. L. Dias
Format:	Artículo científico
Language:	en
Published:	Sociedade Brasileira de Física 2004
Subjects:	Física, Astronomía y Matemáticas
Online Access:	https://www.redalyc.org/articulo.oa?id=46434230
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author	I. F. L. Dias
author_facet	I. F. L. Dias
contents	Thermal expansion contribution to the temperature dependence of excitonic transitions in GaAs and AlGaAs I. F. L. Dias J. L. Duarte E. Laureto J. R. Leite S. A. Lourenço D. O. Toginho Filho L. C. Poças Física, Astronomía y Matemáticas Photoluminescence and photoreflectance measurements have been used to determine excitonic transitions inthe ternary AlxGa1−xAs alloy in the temperature range from 2 to 300 K. The effect of the thermal expansioncontribution on the temperature dependence of excitonic transitions for different aluminum concentrations in theAlxGa1−xAs alloy is presented. Results from this study have shown that the negative thermal expansion (NTE)in the AlxGa1−xAs alloy, in the low temperature interval, induces a small blueshift in the optical transitionenergy. In the temperature range from ∼23 to ∼95 K there is a competition between the NTE effect and theelectron-phonon interaction. Using the thermal expansion coefficient in the 2 300 K temperature range, thethermal expansion contribution to GaAs, at room temperature, represents 21% of the total shift of the excitonictransition energy. After subtracting the thermal expansion contribution from the experimental temperaturedependence of the excitonic transitions, in the AlxGa1−xAs alloy, the contribution to the electron-phononinteraction of the longitudinal optical phonon increases, relatively to the longitudinal acoustical phonon, withincreasing Al concentration. 2004 artículo científico 0103-9733 https://www.redalyc.org/articulo.oa?id=46434230 en http://www.redalyc.org/revista.oa?id=464 Brazilian Journal of Physics application/pdf Sociedade Brasileira de Física Brazilian Journal of Physics (Brasil) Num.2A Vol.34
format	Artículo científico
id	redalyc_46434230
language	en
publishDate	2004
publisher	Sociedade Brasileira de Física
spellingShingle	Thermal expansion contribution to the temperature dependence of excitonic transitions in GaAs and AlGaAs I. F. L. Dias Física, Astronomía y Matemáticas Thermal expansion contribution to the temperature dependence of excitonic transitions in GaAs and AlGaAs I. F. L. Dias J. L. Duarte E. Laureto J. R. Leite S. A. Lourenço D. O. Toginho Filho L. C. Poças Física, Astronomía y Matemáticas Photoluminescence and photoreflectance measurements have been used to determine excitonic transitions inthe ternary AlxGa1−xAs alloy in the temperature range from 2 to 300 K. The effect of the thermal expansioncontribution on the temperature dependence of excitonic transitions for different aluminum concentrations in theAlxGa1−xAs alloy is presented. Results from this study have shown that the negative thermal expansion (NTE)in the AlxGa1−xAs alloy, in the low temperature interval, induces a small blueshift in the optical transitionenergy. In the temperature range from ∼23 to ∼95 K there is a competition between the NTE effect and theelectron-phonon interaction. Using the thermal expansion coefficient in the 2 300 K temperature range, thethermal expansion contribution to GaAs, at room temperature, represents 21% of the total shift of the excitonictransition energy. After subtracting the thermal expansion contribution from the experimental temperaturedependence of the excitonic transitions, in the AlxGa1−xAs alloy, the contribution to the electron-phononinteraction of the longitudinal optical phonon increases, relatively to the longitudinal acoustical phonon, withincreasing Al concentration. 2004 artículo científico 0103-9733 https://www.redalyc.org/articulo.oa?id=46434230 en http://www.redalyc.org/revista.oa?id=464 Brazilian Journal of Physics application/pdf Sociedade Brasileira de Física Brazilian Journal of Physics (Brasil) Num.2A Vol.34
title	Thermal expansion contribution to the temperature dependence of excitonic transitions in GaAs and AlGaAs
topic	Física, Astronomía y Matemáticas
url	https://www.redalyc.org/articulo.oa?id=46434230

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