Determination of surface state density for GaAs and InAlAs by room temperature photoreflectance

Citation
Gs. Chang et al., Determination of surface state density for GaAs and InAlAs by room temperature photoreflectance, J APPL PHYS, 86(3), 1999, pp. 1765-1767
Citations number
9
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
JOURNAL OF APPLIED PHYSICS
ISSN journal
00218979 → ACNP
Volume
86
Issue
3
Year of publication
1999
Pages
1765 - 1767
Database
ISI
SICI code
0021-8979(19990801)86:3<1765:DOSSDF>2.0.ZU;2-E
Abstract
Room temperature photoreflectance (PR) was used to investigate the surface state densities of GaAs and In0.52Al0.48As surface intrinsic-n(+) structure s. The built-in electric field and thus the surface barrier height are eval uated using the observed Franz-Keldysh oscillations in the PR spectra. Base d on the thermionic emission theory and current-transport theory, the surfa ce state density as well as the pinning position of the Fermi level can be determined from the dependence of the surface barrier height on the pump be am intensity. Even though this method is significantly simpler, easier to p erform, and time efficient compared with other approaches, the results obta ined agree with the literature. (C) 1999 American Institute of Physics. [S0 021-8979(99)03815-3].