Optical properties of self-assembled ZnTe quantum dots grown by molecular-beam epitaxy
- Department of Electrophysics, National Chiao Tung University, Hsin-Chu, Taiwan 30010 (China)
The morphology and the size-dependent photoluminescence (PL) spectra of the type-II ZnTe quantum dots (QDs) grown in a ZnSe matrix were obtained. The coverage of ZnTe varied from 2.5 to 3.5 monolayers (MLs). The PL peak energy decreased as the dot size increased. Excitation power and temperature-dependent PL spectra are used to characterize the optical properties of the ZnTe quantum dots. For 2.5- and 3.0-ML samples, the PL peak energy decreased monotonically as the temperature increased. However, for the 3.5-ML sample, the PL peak energy was initially blueshifted and then redshifted as the temperature increased above 40 K. Carrier thermalization and carrier transfer between QDs are used to explain the experimental data. A model of temperature-dependent linewidth broadening is employed to fit the high-temperature data. The activation energy, which was found by the simple PL intensity quenching model, of the 2.5, 3.0, and 3.5 MLs were determined to be 6.35, 9.40, and 18.87 meV, respectively.
- OSTI ID:
- 20665083
- Journal Information:
- Journal of Applied Physics, Vol. 97, Issue 3; Other Information: DOI: 10.1063/1.1834985; (c) 2005 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ACTIVATION ENERGY
CRYSTAL GROWTH
EXCITATION
EXPERIMENTAL DATA
HOLE MOBILITY
MEV RANGE 01-10
MEV RANGE 10-100
MOLECULAR BEAM EPITAXY
MORPHOLOGY
OPTICAL PROPERTIES
PHOTOLUMINESCENCE
QUANTUM DOTS
SEMICONDUCTOR MATERIALS
SPECTRA
SPECTRAL SHIFT
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0013-0065 K
THERMALIZATION
ZINC SELENIDES
ZINC TELLURIDES