Layer perfection in ultrathin InAs quantum wells in GaAs(001)

Journal Article · Sat Jan 15 04:00:00 EST 2000 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PhysRevB.61.2073· OSTI ID:20215221

Gupta, J A ^[1]; Watkins, S P ^[1]; Crozier, E D ^[1]; Woicik, J C ^[2]; Harrison, D A ^[1]; Jiang, D T ^[1]; Pickering, I J ^[3]; Karlin, B A ^[2]

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1. Department of Physics, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6 (Canada)
2. National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States)
3. Stanford Synchrotron Radiation Laboratory, P.O. Box 4349, MS 69, Stanford, California 94309 (United States)

X-ray standing wave (XSW), x-ray diffraction, and photoluminescence (PL) measurements were used to assess the layer perfection and positions of 1 and 1/2 monolayer (ML) InAs quantum wells buried in GaAs(001). Local structure in the 1-ML films was evaluated using x-ray absorption fine structure (XAFS) measurements. Growth temperature effects were studied in a series of samples produced by metal organic vapor phase epitaxy (MOVPE) between 400 and 600 degree sign C. The XSW coherent position of the In atoms decreases with increasing temperature in the 1-ML samples, and the optimal growth temperature is near 550 degree sign C, as evidenced by the coherent position of 1.15{+-}0.02 and the relatively high coherent fraction of 0.72{+-}0.08. With decreasing growth temperature the XSW measurements may suggest segregation of In atoms, which results in an incorporation of the In into multiple layers. The segregation appears to be reduced at the higher temperatures due to the favorable kinetic conditions created in the MOVPE environment. Low-temperature PL measurements indicate that the sharpest and most intense In-excitonic emission is obtained from the 1-ML sample grown at 530 degree sign C. For the (1/2)-ML samples, growth temperatures of 400 and 600 degree sign C produce similar standing wave results, although the PL reveals the higher temperature sample to be of far superior quality, due to excessive carbon incorporation at 400 degree sign C. In-As bond-length distortions found in the XAFS measurements agree with a macroscopic elastic description of the pseudomorphic epitaxy. (c) 2000 The American Physical Society.

• OSTI ID: 20215221
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Journal Name: Physical Review. B, Condensed Matter and Materials Physics Journal Issue: 3 Vol. 61; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
EXCITONS
EXPERIMENTAL DATA
GALLIUM ARSENIDES
INDIUM ARSENIDES
INTERFACES
PHOTOLUMINESCENCE
SEGREGATION
STANDING WAVES
STRUCTURAL CHEMICAL ANALYSIS
THIN FILMS
VAPOR PHASE EPITAXY
X-RAY DIFFRACTION