Growth and characterization of GaAs/AlAs superlattice alloys

Conference · Thu Jan 01 04:00:00 EST 1987

OSTI ID:7077198

Drummond, T J; Jones, E D; Hjalmarson, H P; Doyle, B L

The superlattice bandstructure of short-period GaAs/AlAs superlattices grown by molecular beam epitaxy resembles that of the AlGaAs alloy system. We have studied indirect gap GaAs/AlAs superlattice alloys using x-ray diffraction and pressure dependent magneto-luminescence. Analysis of the x-ray data shows that the AlAs layers are strained to be pseudomorphic with the GaAs substrate. Because the indirect conduction band ground state derives from the AlAs X-point these superlattice alloys must be treated as strained-layer superlattices. Interpretation of luminescence data using Kronig-Penney and tight-binding analyses of the superlattice bandstructure and optical dipole matrix elements shows that this experiment provides a sensitive measure of the conduction band offset for the GaAs/AlAs system. Quantum size effects lift the three-fold degeneracy of the X-point to yield an in-plane X band quantized according to the transverse electron mass (X/sub t/) and a separate X band along the superlattice axis quantized according to the longitudinal electron mass (X/sub 1/). Strain shifts at the X-points are of the same magnitude as quantum size effect shifts and drive the X/sub t/ band toward lower energies. The effect of strain in the conduction band can be accurately modeled by assuming GaP deformation potentials for the AlAs layers.

• Research Organization: Sandia National Labs., Albuquerque, NM (USA)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 7077198
• Report Number(s): SAND-86-2724C; CONF-870385-3; ON: DE87006891
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360602* -- Other Materials-- Structure & Phase Studies
ALUMINIUM ARSENIDES
ALUMINIUM COMPOUNDS
ARSENIC COMPOUNDS
ARSENIDES
COHERENT SCATTERING
DIFFRACTION
ELECTRONIC STRUCTURE
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
LAYERS
LUMINESCENCE
PHOTOLUMINESCENCE
PNICTIDES
SCATTERING
STRAINS
SUPERLATTICES
X-RAY DIFFRACTION