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Electrical transport properties in (111) growth-axis GaAlAs/GaInAs heterostructures 
Auteur(s): Konczewicz L., Jouault B., Contreras S., Sadowski Ml, Robert Jean-Louis, Blanc S., Fontaine C.
(Article) Publié:
Physica Status Solidi B, vol. 223 p.507-512 (2001)
Ref HAL: hal-00544463_v1
Exporter : BibTex | endNote
Résumé: The effect of an internal piezoelectric field on electrical transport phenomena has been studied in GaAlAs/GaInAs heterostructures grown on (001) and (111)B GaAs substrates. The two-dimensional electron gas (2DEG) in the structure was obtained by conventional modulation delta -doping in the barrier layer. The: conductivity and Nail effect were studied at room temperature as a function of hydrostatic pressures up to 1000 MPa. The observed pressure changes of the 2DEG concentration have been compared with theoretical predictions, taking into account the strain-induced electric fields in the barrier layer. The piezoresistive behaviour under uniaxial stress has also been determined. It was found that piezo-effects are more pronounced in the case of the material with the built-in piezoelectric field.
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A novel selectively delta-doped AlGaAs/(In,Ga,As)/GaAs pseudomorphic heterostructure
Auteur(s): Bouzaiene L., Sfaxi L., Sghaeir H., Maaref H., Cavanna A., Jouault B., Contreras S., Konczewicz L.
Conference: Spring Conference of the E-MRS/IUMRS/ICEM (Strasbourg, FR, 2000-05-30)
Actes de conférence: OPTICAL MATERIALS, vol. 17 p.299-303 (2001)
Texte intégral en Openaccess : 
Ref HAL: hal-00544461_v1
DOI: 10.1016/S0925-3467(01)00095-7
WoS: 000169788700066
Exporter : BibTex | endNote
7 Citations
Résumé: We have investigated the electron density of the delta -doped conventional AlGaAs/GaAs and pseudomorphic AlGaAs/InGaAs/GaAs heterojunctions. Shubnikov-de Hass (SdH) and quantum Hall effect measurements at 4.2 K have been carried out to investigate the existence of a quasi-two-dimensional gas (2DEG) in delta Si-doped AlGaAs/GaAs heterostructure. Cases have been also examined where the g-doping is placed in a narrow quantum well within the AlGaAs barrier with an Al concentration in the well (x(Al)(well)) less than in the barrier (x(Al)(Barr)). This is intended to increase the electron density. Secondary-ion mass spectroscopy (SIMS) measurements were also performed on one of these structures in order to demonstrate the spreading of the dopants. To improve the electron density, we have combined in only one structure the delta Si, in a narrow quantum well, and the InGaAs layer introduced at the heterointerface between the AlGaAs and the GaAs. A comparison between the theoretical and experimental results was performed. The variation trends of calculated electron density are in good agreement with the experimental ones. (C) 2001 Published by Elsevier Science B.V.
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Raman, low temperature photoluminescence and transport investigation of N-implanted 6H-SiC
Auteur(s): Thomas P., Contreras S., Juillaguet S., Robert Jean-louis, Camassel J., Gimbert J., Billon T., Jaussaud C.
Conference: 7th International Conference on Silicon Carbide, III-Nitrides and Related Materials (ICSCIII-N 97) (STOCKHOLM (SWEDEN), FR, 1997-08-31)
Actes de conférence: SILICON CARBIDE, III-NITRIDES AND RELATED MATERIALS, PTS 1 AND 2, vol. 264-2 p.725-728 (1998)
Ref HAL: hal-00543782_v1
Exporter : BibTex | endNote
Résumé: We report a combined investigation of Raman, low temperature photoluminescence (LTPL) and high temperature transport measurements performed on nitrogen implanted p-type epitaxial layers of 6H-SiC.
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