Phase Separation and Facet Formation during the Growth of (GaAs)1-x(Ge2)x Alloy Layers by Metal Organic Vapour Phase Epitaxy

Conference · Mon Sep 13 00:00:00 EDT 1999

OSTI ID:12158

Norman, A G; Olson, J M; Geisz, J F; Moutinho, H R; Mason, A; Al-Jassim, M M ^[1]; Vernon, S M ^[2]

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1. National Renewable Energy Laboratory
2. Spire Corporation

Metal organic vapour phase epitaxy (GaAs)1-x(Ge2)x alloy layers, 0<x<0.22, were grown at temperatures between 640 and 690 C, on vicinal (001) GaAs substrates. Phase separation occurred in all the layers. The phase-separated microstructure changed with alloy composition, growth temperature, and substrate orientation. In x {approx} 0.1 layers grown at 640 C, Ge segregation occurred on {l_brace}115{r_brace}B planes associated with a {l_brace}115{r_brace}B surface faceting. Increase in growth temperature led to the formation of large, (001)-oriented, irregular-shaped platelets of Ge-rich material. Growth on {l_brace}115{r_brace}B substrates resulted in a ''natural superlattice'' of GaAs/Ge along the growth direction.

• Research Organization: National Renewable Energy Lab., Golden, CO (US)
• Sponsoring Organization: US Department of Energy (US)
• DOE Contract Number: AC36-99GO10337
• OSTI ID: 12158
• Report Number(s): NREL/CP-520-26319
• Resource Type: Conference paper/presentation
• Conference Information: Microscopy of Semiconducting Materials XI, Oxford (GB), 03/22/1999--03/25/1999
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
ALLOY LAYERS
ALLOYS
ANTIPHASE DOMAINS
BAND-GAP NARROWING
EPITAXY
GAAS
GE
GROWTH TEMPERATURE
MICROSCOPY
MICROSTRUCTURE
MOVPE
MULTI-JUNCTION CELLS
ORIENTATION
PHASE SEPARATION
SEGREGATION
SOLAR CELLS
SUBSTRATES
SUPERLATTICE