Size dependent optical properties of Si quantum dots in Si-rich nitride/Si{sub 3}N{sub 4} superlattice synthesized by magnetron sputtering
- ARC Photovoltaics Centre of Excellence, University of New South Wales, Sydney, New South Wales 2052 (Australia)
- Physics and Advanced Materials, University of Technology Sydney, P. O. Box 123, Broadway, New South Wales 2007 (Australia)
A spectroscopic ellipsometry compatible approach is reported for the optical study of Si quantum dots (QDs) in Si-rich nitride/silicon nitride (SRN/Si{sub 3}N{sub 4}) superlattice, which based on Tauc-Lorentz model and Bruggeman effective medium approximation. It is shown that the optical constants and dielectric functions of Si QDs are strongly size dependent. The suppressed imaginary dielectric function of Si QDs exhibits a single broad peak analogous to amorphous Si, which centered between the transition energies E{sub 1} and E{sub 2} of bulk crystalline Si and blue shifted toward E{sub 2} as the QD size reduced. A bandgap expansion observed by the TL model when the size of Si QD reduced is in good agreement with the PL measurement. The bandgap expansion with the reduction of Si QD size is well supported by the first-principles calculations based on quantum confinement.
- OSTI ID:
- 21538176
- Journal Information:
- Journal of Applied Physics, Vol. 109, Issue 6; Other Information: DOI: 10.1063/1.3561439; (c) 2011 American Institute of Physics; ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
77 NANOSCIENCE AND NANOTECHNOLOGY
DEPOSITION
DIELECTRIC MATERIALS
ELECTRON MICROSCOPY
ELLIPSOMETRY
ENERGY GAP
EXPANSION
MAGNETRONS
OPTICAL PROPERTIES
PEAKS
QUANTUM DOTS
RESOLUTION
SEMICONDUCTOR MATERIALS
SILICON
SILICON NITRIDES
SPECTRAL SHIFT
SPUTTERING
STRAINS
SUPERLATTICES
ELECTRON TUBES
ELECTRONIC EQUIPMENT
ELEMENTS
EQUIPMENT
MATERIALS
MEASURING METHODS
MICROSCOPY
MICROWAVE EQUIPMENT
MICROWAVE TUBES
NANOSTRUCTURES
NITRIDES
NITROGEN COMPOUNDS
PHYSICAL PROPERTIES
PNICTIDES
SEMIMETALS
SILICON COMPOUNDS