Temperature dependent and time-resolved photoluminescence studies of InAs self-assembled quantum dots with InGaAs strain reducing layer structure

Journal Article · Wed Jul 01 00:00:00 EDT 2009 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3159648· OSTI ID:21359282

Lingmin, Kong ^[1]; Zhechuan, Feng ^[2]; Zhengyun, Wu ^[3]; Weijie, Lu ^[4]

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1. Department of Physics, Zhejiang Ocean University, Zhoushan 316000 (China)
2. Department of Electrical Engineering, and Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 106-17, Taiwan (China)
3. Department of Physics, Xiamen University, Xiamen 361005 (China)
4. Department of Chemistry, Fisk University, Nashville, Tennessee 37208 (United States)

Four types of self-assembled InAs/GaAs quantum dots (QDs) were grown by molecular beam epitaxy and studied via temperature-dependent and time-resolved photoluminescence (PL) spectroscopy measurements. A thin InGaAs stain reducing layer (SRL) is adopted which extends the emission wavelength to 1.3 mum and the influence of strain on QDs is investigated. The SRL releases the strain between the wetting layer and QDs, and enlarges the size of QDs, as shown by atomic force microscopy measurements. As the thickness of InAs layer decreases to 1.7 ML, the QDs with the SRL are chained to strings and the density of QDs increases significantly, which leads to an abnormal redshift of 1.3 mum PL peak at room temperature. PL peaks of InAs QDs with the SRL show redshift compared with the QDs directly deposited on GaAs matrix. The dependences of PL lifetime on the QD size, density and temperature (T) are systematically studied. It is observed that the PL lifetime of QDs is insensitive to T below 50 K. Beyond 50 K, increases and then drops at higher temperature, with a peak at T{sub C}, which was determined by the SRL and the thickness of InAs. We have also observed an obvious PL spectral redshift of the QDs with 1.7 ML InAs coverage on SRL at low T as the measuring time delays. The PL lifetime of QDs with the SRL is smaller than that of QDs without the SRL. The QDs with different densities have different PL lifetime dependence on the QDs size. These observations can be explained by the competition between the carrier redistribution and thermal emission.

• OSTI ID: 21359282
• Journal Information: Journal of Applied Physics, Vol. 106, Issue 1; Other Information: DOI: 10.1063/1.3159648; (c) 2009 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

77 NANOSCIENCE AND NANOTECHNOLOGY
ATOMIC FORCE MICROSCOPY
CRYSTAL GROWTH
GALLIUM ARSENIDES
INDIUM ARSENIDES
MOLECULAR BEAM EPITAXY
PHOTOLUMINESCENCE
QUANTUM DOTS
RED SHIFT
SEMICONDUCTOR MATERIALS
SPECTROSCOPY
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0013-0065 K
TEMPERATURE RANGE 0273-0400 K
THICKNESS
THIN FILMS
TIME DELAY
TIME RESOLUTION
ARSENIC COMPOUNDS
ARSENIDES
CRYSTAL GROWTH METHODS
DIMENSIONS
EMISSION
EPITAXY
FILMS
GALLIUM COMPOUNDS
INDIUM COMPOUNDS
LUMINESCENCE
MATERIALS
MICROSCOPY
NANOSTRUCTURES
PHOTON EMISSION
PNICTIDES
RESOLUTION
TEMPERATURE RANGE
TIMING PROPERTIES