Temperature-dependent transport properties of InAs films grown on lattice-mismatched GaP

Citation
V. Gopal et al., Temperature-dependent transport properties of InAs films grown on lattice-mismatched GaP, J APPL PHYS, 87(3), 2000, pp. 1350-1355
Citations number
25
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
JOURNAL OF APPLIED PHYSICS
ISSN journal
00218979 → ACNP
Volume
87
Issue
3
Year of publication
2000
Pages
1350 - 1355
Database
ISI
SICI code
0021-8979(20000201)87:3<1350:TTPOIF>2.0.ZU;2-D
Abstract
Hall effect and electrical resistivity measurements were carried out on und oped InAs thin films grown by molecular-beam epitaxy directly on (001) GaP substrates. The large lattice mismatch between these two compounds results in a high density array of misfit dislocations at the heterointerface and t hreading dislocations in the InAs epilayer. The threading dislocation densi ty varies with epilayer thickness, with the largest proportion being presen t near the heterointerface. This leads to variation of both the carrier con centration and electron mobility with thickness. Consequently, a multilayer analysis was used to interpret the transport data. This analysis yields a temperature-independent carrier concentration, which indicates degenerate d onor levels in this narrow band-gap material. Room temperature mobilities i n excess of 10 000 cm(2)/V s were obtained for thick InAs layers despite di slocation densities of 10(10) cm(-2). The relative insensitivity of the mob ility to temperature suggests that temperature-independent scattering domin ates over ionized impurity/defect and phonon scattering. (C) 2000 American Institute of Physics. [S0021-8979(00)05603-6].