Optical and structural properties of molecular-beam epitaxial GaAs on sapphire

Journal Article · Wed Mar 01 04:00:00 EST 1989 · J. Vac. Sci. Technol., B; (United States)

DOI:https://doi.org/10.1116/1.584734· OSTI ID:6406743

Chin, A; Bhattacharya, P; Chang, K H; Biswas, D

We have evaluated the structural and optical properties of GaAs grown by molecular-beam epitaxy on (0001) and (011-bar2)-oriented sapphire substrates for possible direct deposition on sapphire optical fibers and optoelectronic device applications. X-ray diffraction studies and cross-sectional transmission electron microscopy measurements show that the GaAs films are single-crystal and have a (111) orientation for both substrate orientations. Both x-ray and temperature-dependent photoluminescence measurements indicate that the quality of the GaAs films is better for the (011-bar2) sapphire orientation. The best results are produced when growth is initiated at a very slow rate (/similar to/0.1 ..mu..m/h) and low temperature (/similar to/400 /sup 0/C) followed by growth parameters for normal homoepitaxial GaAs (1 ..mu..m/h, 560--600 /sup 0/C). The incorporation of a graded band gap strained layer in InGaAs/GaAs superlattice near the sapphire--GaAs interface also improves the optical quality of the GaAs films. Low-temperature photoluminescence spectra is dominated by a peak at 1.49--1.495 eV, with a best linewidth of 26.9 meV, which we believe is due to an integration of several impurity and defect related bound exciton transitions. A peak to lower energies by /similar to/60 meV is thought to be due to acceptorlike impurity defect complexes. Post growth short term halogen lamp annealing marginally improves the overall luminescence intensity of the samples. A linewidth of 20 meV is measured for a (80 A) GaAs/(120 A) Al/sub 0.3/ Ga/sub 0.7/ As multiquantum grown on sapphire.

• Research Organization: Solid State Electronics Laboratory, Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109-2122
• OSTI ID: 6406743
• Journal Information: J. Vac. Sci. Technol., B; (United States), Journal Name: J. Vac. Sci. Technol., B; (United States) Vol. 7:2; ISSN JVTBD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360602* -- Other Materials-- Structure & Phase Studies
360603 -- Materials-- Properties
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
ARSENIC COMPOUNDS
ARSENIDES
CHALCOGENIDES
COHERENT SCATTERING
CORUNDUM
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
CRYSTALS
DIFFRACTION
ELECTRON MICROSCOPY
ENERGY GAP
EPITAXY
EXCITONS
FIBERS
FILMS
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
HIGH TEMPERATURE
LUMINESCENCE
MICROSCOPY
MINERALS
MOLECULAR BEAM EPITAXY
MONOCRYSTALS
OPTICAL FIBERS
OPTICAL PROPERTIES
ORIENTATION
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PHOTOLUMINESCENCE
PHYSICAL PROPERTIES
PNICTIDES
QUASI PARTICLES
SAPPHIRE
SCATTERING
TEMPERATURE DEPENDENCE
THIN FILMS
TRANSMISSION ELECTRON MICROSCOPY
USES
X-RAY DIFFRACTION