Effect of annealing on the nonequilibrium carrier lifetime in GaAs grown at low temperatures

Journal Article · Thu Aug 15 04:00:00 EDT 2013 · Semiconductors

DOI:https://doi.org/10.1134/S1063782613080150· OSTI ID:22210574

Pastor, A. A.; Prokhorova, U. V.; Serdobintsev, P. Yu. ^[1]; Yagovkina, M. A. ^[2]

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1. St. Petersburg State University, Staryi Petergof (Russian Federation)
2. Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation)

GaAs samples grown by molecular-beam epitaxy at low (230 Degree-Sign C) temperatures are investigated. One of the samples is subjected to aftergrowth annealing at 600 Degree-Sign C. Using an unconventional pump-probe scheme for measuring the dynamic variation in the light refractive index, the nonequilibrium charge-carrier lifetime (275 {+-} 30 fs before annealing) is determined. Such a short carrier lifetime in the unannealed material is due to the high concentration of point defects, mainly As{sub Ga} antisite defects. According to X-ray diffraction and steady-state optical absorption data, the As{sub Ga} concentration in the samples is 3 Multiplication-Sign 10{sup 19} cm{sup -3}, which corresponds to an arsenic excess of 0.26 at %. Upon annealing at 600 Degree-Sign C, the superstoichiometric As defects self-organize and form As nanoinclusions in the GaAs crystal matrix. It is shown that in this case the nonequilibrium charge-carrier lifetime increases to 452 {+-} 5 fs. This lifetime is apparently ensured by the capture of non-equilibrium charge carriers at metal As nanoinclusions.

• OSTI ID: 22210574
• Journal Information: Semiconductors, Journal Name: Semiconductors Journal Issue: 8 Vol. 47; ISSN SMICES; ISSN 1063-7826
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ABSORPTION
ANNEALING
ARSENIC
CARRIER LIFETIME
CHARGE CARRIERS
CRYSTALS
GALLIUM ARSENIDES
MOLECULAR BEAM EPITAXY
POINT DEFECTS
REFRACTIVE INDEX
X-RAY DIFFRACTION