Growth and characterization of GaAs/Ge epilayers grown on Si substrates by molecular beam epitaxy

Journal Article · Sun Dec 01 00:00:00 EST 1985 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.335551· OSTI ID:6392238

Sheldon, P; Yacobi, B G; Jones, K M; Dunlavy, D J

Epitaxial GaAs/Ge films are grown by molecular beam epitaxy (MBE) on Si substrates. The effect of various MBE growth conditions on the sample morphology, the defect density, and the optical properties of GaAs and Ge epilayers is examined. Scanning electron microscopy, plan-view and cross-sectional transmission electron microscopy, reflection high-energy electron diffraction, and photoluminescence are used to characterize epitaxial layers. It is found that the defect density decreases with increasing epilayer thickness. This is due to an annihilation process that affects both threading dislocations and stacking faults. The substrate temperature during Ge growth is found to affect the properties of both the Ge and GaAs films. GaAs surface morphology degrades and the stacking fault density increases at high Ge buffer-layer substrate temperatures; however, the threading dislocation density remains unchanged. Variations in growth conditions are correlated with defect densities and luminescence efficiencies to determine material quality and optimize growth conditions.

• Research Organization: Solar Energy Research Institute, Golden, Colorado 80401
• DOE Contract Number: AC02-83CH10093
• OSTI ID: 6392238
• Journal Information: J. Appl. Phys.; (United States), Vol. 58:11
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
14 SOLAR ENERGY
GALLIUM ARSENIDES
CRYSTAL DEFECTS
MOLECULAR BEAM EPITAXY
MORPHOLOGY
OPTICAL PROPERTIES
GERMANIUM
SILICON
VAPOR DEPOSITED COATINGS
CRYSTAL STRUCTURE
DISLOCATIONS
EFFICIENCY
ELECTRON DIFFRACTION
LUMINESCENCE
PHOTOLUMINESCENCE
SCANNING ELECTRON MICROSCOPY
STACKING FAULTS
THICKNESS
TRANSMISSION ELECTRON MICROSCOPY
ARSENIC COMPOUNDS
ARSENIDES
COATINGS
COHERENT SCATTERING
DIFFRACTION
DIMENSIONS
ELECTRON MICROSCOPY
ELEMENTS
EPITAXY
GALLIUM COMPOUNDS
LINE DEFECTS
METALS
MICROSCOPY
PHYSICAL PROPERTIES
PNICTIDES
SCATTERING
SEMIMETALS
360601* - Other Materials- Preparation & Manufacture
140501 - Solar Energy Conversion- Photovoltaic Conversion