TY - JOUR
T1 - Photoreflectance spectroscopy of AlGaAs/GaAs heterostructures with a two-dimensional electron gas system
AU - Méndez-García, V. H.
AU - Zamora, L.
AU - Lastras-Martinez, A.
AU - Saucedo, N.
AU - Peña, R.
AU - Guillén, A.
AU - Rivera, Z.
AU - Meléndez, M.
AU - López, M.
AU - Hernández, F.
AU - Huerta, J.
N1 - Funding Information:
Méndez-Garcı́a V. H. Zamora L. Lastras-Martinez A. Saucedo N. Instituto de Investigación Comunicación Optica, Universidad Autónoma de San Luis Potosi, Av. Karakorum 1470, Lomas 4a Sección, San Luis Potosi 78210, S.L.P., Mexico Peña R. Guillén A. Rivera Z. Meléndez M. López M. Centro de Investigación y Estudios Avanzados del IPN, México 07000, Distrito Federal, Mexico Hernández F. Huerta J. Centro de Investigación en Ciencia Aplicada y Tecnologia, Avanzada del IPN, Mexico, Distrito Federale, Mexico Centro Nacional de Metrologı́a, Municipio el Marqués, 76900 Querétaro, Mexico 05 2002 20 3 1238 1242 1 November 2001 14 January 2002 2002-06-05T10:56:44 2002 American Vacuum Society We report a study of AlGaAs/GaAs semiconductor heterostructures with a two-dimensional electron gas system grown under different conditions by molecular beam epitaxy in three different laboratories. We performed photoreflectance (PR) measurements of this set of samples and analyzed the Franz–Keldysh oscillations associated with the E 0 transition of GaAs. We found that the sample with the highest electron mobility, as observed in Hall measurements at 77 K exhibited the lowest electric field strength. In addition, the 12 K photoluminescence (PL) spectra of the samples revealed intense and narrow free exciton luminescence in the sample with the highest electron mobility, while samples with lower mobility values showed impurities related PL lines. It is suggested that the electron mobility is affected by unintentional C impurities, which act like dispersion centers in the 2-DEG and increase the internal electric fields in the GaAs region. On the other hand, the PR spectra close to the AlGaAs band-gap energy region presented broad PR signals, due to the Si-doping in the alloy. The sample with the highest quality presented the most intense AlGaAs PR signal. We believe that low AlGaAs PR signal intensities are caused by unintentional incorporation of impurities during the preparation of the samples, which degrade the optical properties of the alloy. (Al,Ga)As GaAs Papers from the 20th North American Conference on Molecular Beam Epitaxy Providence, Rhode Island (USA) 1-3 October 2001
PY - 2002/5
Y1 - 2002/5
N2 - A study of AlGaAs/GaAs semiconductor heterostructures with a two-dimensional electron gas (2-DEG) system grown under different conditions by molecular beam epitaxy was presented. It was found that the sample with highest electron mobility exhibited the lowest electric field strength. The analysis suggested that the electron mobility was affected by unintentional C impurities which acted like dispersion centers in the 2-DEG and increased the internal electric fields in the GaAs region.
AB - A study of AlGaAs/GaAs semiconductor heterostructures with a two-dimensional electron gas (2-DEG) system grown under different conditions by molecular beam epitaxy was presented. It was found that the sample with highest electron mobility exhibited the lowest electric field strength. The analysis suggested that the electron mobility was affected by unintentional C impurities which acted like dispersion centers in the 2-DEG and increased the internal electric fields in the GaAs region.
UR - http://www.scopus.com/inward/record.url?scp=0035998563&partnerID=8YFLogxK
U2 - 10.1116/1.1459460
DO - 10.1116/1.1459460
M3 - Artículo de la conferencia
AN - SCOPUS:0035998563
SN - 1071-1023
VL - 20
SP - 1238
EP - 1242
JO - Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures
JF - Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures
IS - 3
T2 - 20th North American Conference on Molecular Beam Epitaxy
Y2 - 1 October 2001 through 3 October 2001
ER -