Electronic parameters of the two-dimensional electron gas in modulation-doped single quantum wells due to an embedded deep step layer

Citation
Tw. Kim et al., Electronic parameters of the two-dimensional electron gas in modulation-doped single quantum wells due to an embedded deep step layer, J APPL PHYS, 89(5), 2001, pp. 2649-2652
Citations number
19
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
JOURNAL OF APPLIED PHYSICS
ISSN journal
0021-8979 → ACNP
Volume
89
Issue
5
Year of publication
2001
Pages
2649 - 2652
Database
ISI
SICI code
0021-8979(20010301)89:5<2649:EPOTTE>2.0.ZU;2-T
Abstract
The Shubnikov-de Haas (S-dH) measurements at 1.5 K clearly demonstrated the existence of a two-dimensional electron gas (2DEG) in the modulation-doped Al0.25Ga0.75As/InyGa1-yAs/GaAs single and step quantum wells, and the fast Fourier transformation results for the S-dH data clearly indicated the ele ctron occupation of one subband in the asymmetric single and step quantum w ells. While the electron carrier density of the 2DEG in the step quantum we ll was larger than that in the single quantum well due to the larger conduc tion-band discontinuities, the mobility of the 2DEG in the step quantum wel l was smaller than that in the single quantum well because of the interface scattering resulting from the embedded step well. The electron effective m ass in the step quantum well was smaller than that in the single quantum we ll, which was consistent with a smaller mass of the embedded deep step laye r. The electronic subband energy, the energy wave function, and the Fermi e nergy in the InyGa1-yAs step quantum wells were calculated by using a self- consistent method taking into account exchange-correlation effects together with strain and nonparabolicity effects. (C) 2001 American Institute of Ph ysics.