ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Due to the fact that impurities normally change their doping characters when they undergo shallow to deep transitions or deep-to-false-valence transitions, a single defect, such as a cation on an Sb site, can explain all of the following facts for nonintentionally doped AlxGa1−xSb alloys and InAs/AlxGa1−xSb superlattices and quantum-well structures: (i) Bulk GaSb is p type; (ii) bulk AlSb is semi-insulating; (iii) InAs/AlSb superlattices with InAs quantum wells thicker than a critical thickness dc(x=1.0) are n type, where the InAs shallow–deep critical thickness function dc(x) is around (approximately-equal-to)100–(approximately-equal-to)150 A(ring) for 0.5〈x≤1.0 for InAs/AlxGa1−xSb superlattices; (iv) InAs/AlSb superlattices with InAs quantum wells thinner than dc(x=1.0) are semi-insulating. In addition, the theory predicts that Al0.5Ga0.5Sb and AlSb will be semi-insulating when nonintentionally doped, but can be converted to p type by the application of hydrostatic pressure P: P(approximately-greater-than)90 kbar and P(approximately-greater-than)150 kbar, respectively. These changes of doping character, which lie outside the conventional effective-mass theory, occur often in type-II band-alignment systems, such as InAs/AlxGa1−xSb.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.353450
Permalink