Effect of spacer layer thickness on structural and optical properties of multi-stack InAs/GaAsSb quantum dots

Journal Article · Mon Oct 26 04:00:00 EDT 2015 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4934695· OSTI ID:22485975

Kim, Yeongho; Ban, Keun-Yong; Honsberg, Christiana B. ^[1]; Boley, Allison; Smith, David J. ^[2]

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1. School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85287 (United States)
2. Department of Physics, Arizona State University, Tempe, Arizona 85287 (United States)

The structural and optical properties of ten-stack InAs/GaAsSb quantum dots (QDs) with different spacer layer thicknesses (d{sub s} = 2, 5, 10, and 15 nm) are reported. X-ray diffraction analysis reveals that the strain relaxation of the GaAsSb spacers increases linearly from 0% to 67% with larger d{sub s} due to higher elastic stress between the spacer and GaAs matrix. In addition, the dislocation density in the spacers with d{sub s} = 10 nm is lowest as a result of reduced residual strain. The photoluminescence peak energy from the QDs does not change monotonically with increasing d{sub s} due to the competing effects of decreased compressive strain and weak electronic coupling of stacked QD layers. The QD structure with d{sub s} = 10 nm is demonstrated to have improved luminescence properties and higher carrier thermal stability.

• OSTI ID: 22485975
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 17 Vol. 107; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CARRIERS
DISLOCATIONS
GALLIUM ARSENIDES
INDIUM ARSENIDES
LAYERS
OPTICAL PROPERTIES
PHOTOLUMINESCENCE
QUANTUM DOTS
STRAINS
STRESSES
THICKNESS
X-RAY DIFFRACTION