High-density InAs/GaAs{sub 1−x}Sb{sub x} quantum-dot structures grown by molecular beam epitaxy for use in intermediate band solar cells

Journal Article · Mon Mar 21 00:00:00 EDT 2016 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4943631· OSTI ID:22596616

Mishima, T. D.; Santos, M. B.; Cheng, Y.; Whiteside, V. R.; Sellers, I. R. ^[1]; Hossain, K. ^[2]; Laghumavarapu, R. B.; Liang, B. L.; Huffaker, D. L. ^[3]

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1. Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, Oklahoma 73019 (United States)
2. Amethyst Research, Inc., 123 Case Circle, Ardmore, Oklahoma 73401 (United States)
3. California NanoSystems Institute and Electrical Engineering Department, University of California-Los Angeles (UCLA), Los Angeles, California 90095 (United States)

InAs quantum-dot structures were grown using a GaAs{sub 1−x}Sb{sub x} matrix on a GaAs(001) substrate. The use of GaAs{sub 1−x}Sb{sub x} for the buffer and cap layers effectively suppressed coalescence between dots and significantly increased the dot density. The highest density (∼3.5 × 10{sup 11}/cm{sup 2}) was obtained for a nominal 3.0 monolayer deposition of InAs with an Sb composition of x = 13–14% in the GaAs{sub 1−x}Sb{sub x} matrix. When the Sb composition was increased to 18%, the resulting large photoluminescent red shift (∼90 meV) indicated the release of compressive strain inside the quantum dots. For x > 13%, we observed a significant decrease in photoluminescence intensity and an increase in the carrier lifetime (≥4.0 ns). This is attributed to the type-II band alignment between the quantum dots and matrix material.

• OSTI ID: 22596616
• Journal Information: Journal of Applied Physics, Vol. 119, Issue 11; Other Information: (c) 2016 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALIGNMENT
BUFFERS
CARRIER LIFETIME
CARRIERS
COALESCENCE
DENSITY
DEPOSITION
GALLIUM ARSENIDES
INDIUM ARSENIDES
LAYERS
MATRICES
MATRIX MATERIALS
MEV RANGE 10-100
MOLECULAR BEAM EPITAXY
MOLECULAR BEAMS
PHOTOLUMINESCENCE
QUANTUM DOTS
RED SHIFT
SOLAR CELLS
STRAINS