SIMPLE QUANTUM CONFINEMENT THEORY FOR EXCITON IN INDIRECT GAP NANOSTRUCTURES

We propose in this work a simple quantum confinement theory for excitons based on the effective mass approximation, for investigation of optical properties of indirect gap nanostructures. We show that using this simple model, we can get the analytic solutions and reobtain the main tight-binding approximation numerical results of Hill et al.1 for silicon nanostructures: blue shift of band gap and increase overlap between the states at the band edges when the nanostructures size in decreased.

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Luminescent Amorphous Silicon Layers

MRS Proceedings ◽

10.1557/proc-486-299 ◽

1997 ◽

Vol 486 ◽

Cited By ~ 1

Author(s):

G. Allan ◽

C. Delerue ◽

M. Lannoo

Keyword(s):

Electronic Structure ◽

Amorphous Silicon ◽

Radiative Recombination ◽

Crystalline Silicon ◽

Tight Binding ◽

Blue Shift ◽

Localized States ◽

Structure Model ◽

Radiative Recombination Rate ◽

Tight Binding Approximation

AbstractThe electronic structure of amorphous silicon layers has been calculated within the empirical tight binding approximation using the Wooten-Winer-Weaire atomic structure model. We predict an important blue shift due to the confinement for layer thickness below 3 nm and we compare with crystalline silicon layers. The radiative recombination rate is enhanced by the disorder and the confinement but remains quite small. The comparison of our results with experimental results shows that the density of defects and localized states in the studied samples must be quite small.

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Dimensionality Dependence of Optical Properties and Quantum Confinement Effects of Hydrogenated Silicon Nanostructures

The Journal of Physical Chemistry B ◽

10.1021/jp063895w ◽

2006 ◽

Vol 110 (43) ◽

pp. 21528-21535 ◽

Cited By ~ 12

Author(s):

Man-Fai Ng ◽

R. Q. Zhang

Keyword(s):

Optical Properties ◽

Quantum Confinement ◽

Silicon Nanostructures ◽

Confinement Effects ◽

Hydrogenated Silicon ◽

Quantum Confinement Effects

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Quantum size effects on the optical properties of nc-Si QDs embedded in an a-SiOx matrix synthesized by spontaneous plasma processing

Physical Chemistry Chemical Physics ◽

10.1039/c4cp05126b ◽

2015 ◽

Vol 17 (7) ◽

pp. 5063-5071 ◽

Cited By ~ 11

Author(s):

Debajyoti Das ◽

Arup Samanta

Keyword(s):

Optical Properties ◽

Size Effects ◽

Quantum Confinement ◽

Plasma Processing ◽

Blue Shift ◽

Quantum Size Effects ◽

Confinement Effects ◽

Quantum Size ◽

Quantum Confinement Effects ◽

Stokes Shifts

An energy blue shift due to quantum confinement effects in tiny nc-Si QDs accompanied by larger Stokes shifts in PL at smaller dimensions.

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Photoluminescence of Silicon Nanostructures Formed by Ion Beam Implantation

MRS Proceedings ◽

10.1557/proc-279-201 ◽

1992 ◽

Vol 279 ◽

Cited By ~ 2

Author(s):

D. A. Redman ◽

D. M. Follstaedt ◽

T. Guilinger ◽

M. Kelly

Keyword(s):

Quantum Confinement ◽

Ion Beam ◽

Subsurface Layer ◽

Blue Shift ◽

Nanometer Scale ◽

Silicon Nanostructures ◽

Porous Si ◽

Ion Beam Implantation ◽

Scale Structures ◽

Confinement Model

ABSTRACTA new method was used to fabricate nanometer-scale structures in Si for photoluminescence (PL) studies. He ions were implanted to form a dense subsurface layer of small cavities (1–8 nm diameters). The implanted specimens were either annealed in H or anodized with HF to evaluate the quantum confinement model for PL from porous Si. Incomplete passivation apparently prevented PL in the H-annealed specimens. Implantation combined with anodization produced a substantial blue shift relative to anodization alone, which is consistent with quantum confinement.

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Production of Zinc Oxide Nanoparticles by Liquid Phase Processing: an Investigation on Optical Properties

Materials Science Forum ◽

10.4028/www.scientific.net/msf.553.252 ◽

2007 ◽

Vol 553 ◽

pp. 252-256 ◽

Cited By ~ 15

Author(s):

Mehran Vafaee ◽

Hossein Youzbashizade

Keyword(s):

Zinc Oxide ◽

Optical Properties ◽

Absorption Spectrum ◽

Liquid Phase ◽

Quantum Confinement ◽

Zinc Oxide Nanoparticles ◽

Quantum Confinement Effect ◽

Blue Shift ◽

Oxide Nanoparticles ◽

Zno Nanoparticle

In the recent years, many researchers have been interested in nanoparticles because of their unique properties. In this study, a method for producing ZnO nanoparticle colloids is proposed. The colloids were characterized by spectroscopic analyzer. By absorption spectrum study, we found out that colloids were consisted of nanoparticles with less than 10 nanometer size. The quantum confinement effect in these spectrums was recognized through blue shift of onset absorption wavelengths. These wavelengths shift from 370 nm to 340 nm by decreasing the particles size. Transmittion electron micrographs showed formation of zinc oxide nanoparticles.

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Unified Drain Current Model of Armchair Graphene Nanoribbons with Uniaxial Strain and Quantum Effect

Journal of Nanomaterials ◽

10.1155/2014/219719 ◽

2014 ◽

Vol 2014 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

EngSiew Kang ◽

Razali Ismail

Keyword(s):

Quantum Confinement ◽

Graphene Nanoribbons ◽

Quantum Effect ◽

Current Model ◽

Tight Binding ◽

Drain Current ◽

Published Data ◽

Tight Binding Approximation ◽

Armchair Graphene Nanoribbons ◽

Armchair Graphene

A unified current-voltageI-Vmodel of uniaxial strained armchair graphene nanoribbons (AGNRs) incorporating quantum confinement effects is presented in this paper. TheI-Vmodel is enhanced by integrating both linear and saturation regions into a unified and precise model of AGNRs. The derivation originates from energy dispersion throughout the entire Brillouin zone of uniaxial strained AGNRs based on the tight-binding approximation. Our results reveal the modification of the energy band gap, carrier density, and drain current upon strain. The effects of quantum confinement were investigated in terms of the quantum capacitance calculated from the broadening density of states. The results show that quantum effect is greatly dependent on the magnitude of applied strain, gate voltage, channel length, and oxide thickness. The discrepancies between the classical calculation and quantum calculation were also measured and it has been found to be as high as 19% drive current loss due to the quantum confinement. Our finding which is in good agreement with the published data provides significant insight into the device performance of uniaxial strained AGNRs in nanoelectronic applications.

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