Reflectance difference spectroscopy of GaAs asymmetric surface quantum wells above the fundamental gap

Authors
Lastras-Martinez, LF Santos, PV Ronnow, D Cardona, M Specht, P Eberl, K
Citation
Lf. Lastras-martinez et al., Reflectance difference spectroscopy of GaAs asymmetric surface quantum wells above the fundamental gap, PHYS ST S-A, 170(2), 1998, pp. 317-321
Citations number
12
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
PHYSICA STATUS SOLIDI A-APPLIED RESEARCH
ISSN journal
00318965 → ACNP
Volume
170
Issue
2
Year of publication
1998
Pages
317 - 321
Database
ISI
SICI code
0031-8965(199812)170:2<317:RDSOGA>2.0.ZU;2-X
Abstract
We report Reflectance Difference (RD) measurements on (001) GaAs surface qu antum wells (QW) under Ultra High Vacuum (UHV) conditions from 1.7 to 5.0 e V. The QW is embedded between an arsenic-rich reconstructed GaAs surface an d an AlAs barrier. The samples, grown by MBE with a protective arsenic cap layer, were heated to 320 and 430 degrees C to desorb the As layer and form c(4 x 4) and (2 x 4) surface reconstructions, respectively. By modifying t he surface reconstruction, we are able to separate the contributions to the optical anisotropy from the surface region (mainly associated with the As dimers) from those originating below the surface.