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Optics and Spectroscopy of Exciton States in Quasi - Zero - Dimensional Nanostruсtures: Theory
Issue:
Volume 3, Issue 6-1, November 2014
Pages:
1-1
Received:
9 July 2014
Accepted:
15 July 2014
Published:
31 July 2014
Abstract: The review analyzes the results of theoretical investigations of excitons states (electron - hole pairs states) in a quasi - zero - dimensional nanosystems consisting of spherical semiconductor nanocrystals (quantum dots) placed in transparent dielectric matrices. The theory of exciton states in a quantum dot under conditions of dominating polarization interaction of an electron and a hole with a spherical (quantum dot – dielectric matrix) interface are developed. An shown, that the energy spectrum of heavy hole in the valence band quantum dot is equivalent to the spectrum of hole carrying out oscillator vibrations in the adiabatic electron potential. We show that the absorption and emission edge of quantum dots is formed by two transitions of comparable intensity from different hole size – quantization levels and into a lower electron size – quantization level. Propose a theoretical prospect of using hole transitions between equidistant series of quantum levels observed in nanocrystals for desining a nanolaser. The theory of an exciton formed from spatially separated electron and hole (the hole is in the quantum dot volume, and the electron is localized at the outer spherical quantum dot–dielectric matrix interface) is developed within the modified effective mass method. The effect of significantly increasing the exciton binding energy in quantum dots of zinc selenide, synthesized in a borosilicate glass matrix, relative to that in a zinc selenide single crystal is revealed. We developed the theory of a biexcitons formed from spatially separated electrons and holes (the hole is in quantum dot volume, and the electron is localized at the outer surface of the quantum dot – dielectric matrix interface) in a nanosystem that consists of zinc selenide quantum dots synthesized in a glassy matrix.
Abstract: The review analyzes the results of theoretical investigations of excitons states (electron - hole pairs states) in a quasi - zero - dimensional nanosystems consisting of spherical semiconductor nanocrystals (quantum dots) placed in transparent dielectric matrices. The theory of exciton states in a quantum dot under conditions of dominating polariza...
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Exciton States Spectroscopy in Quasi - Zero - Dimensional Nanostruсtures: Theory
Issue:
Volume 3, Issue 6-1, November 2014
Pages:
2-9
Received:
9 July 2014
Accepted:
15 July 2014
Published:
31 July 2014
Abstract: The theory of exciton states in a quantum dot under conditions of dominating polarization interaction of an electron and a hole with a spherical (quantum dot – dielectric matrix) interface is developed. An shown, that the energy spectrum of heavy hole in the valence band quantum dot is equivalent to the spectrum of hole carrying out oscillator vibrations in the adiabatic electron potential. In the framework of the dipole approximation studied interband absorption of light in a quasi - zero - dimensional nanosystems. We show that the absorption and emission edge of quantum dots is formed by two transitions of comparable intensity from different hole size – quantization levels and into a lower electron size – quantization level. Propose a theoretical prospect of using hole transitions between equidistant series of quantum levels observed in nanocrystals for desining a nanolaser.
Abstract: The theory of exciton states in a quantum dot under conditions of dominating polarization interaction of an electron and a hole with a spherical (quantum dot – dielectric matrix) interface is developed. An shown, that the energy spectrum of heavy hole in the valence band quantum dot is equivalent to the spectrum of hole carrying out oscillator vibr...
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Theory of Excitons and Excitonic Quasimolecules Formed from Spatially Separated Electrons and Holes in Quasi - Zero - Dimensional Nanosystems
Issue:
Volume 3, Issue 6-1, November 2014
Pages:
10-21
Received:
9 July 2014
Accepted:
15 July 2014
Published:
31 July 2014
Abstract: The theory of an exciton formed from spatially separated electron and hole (the hole is in the quantum dot volume, and the electron is localized at the outer spherical quantum dot–dielectric matrix interface) is developed within the modified effective mass method. The effect of significantly increasing the exciton binding energy in quantum dots of zinc selenide, synthesized in a borosilicate glass matrix, relative to that in a zinc selenide single crystal is revealed. It was shown that the short-wavelength shift of the peak of the low-temperature luminescence spectrum of samples containing zinc-selenide quantum dots, observed under the experimental conditions, is caused by quantum confinement of the ground-state energy of the exciton with a spatially separated electron and hole. A review devoted to the theory of excitonic quasimolecules (biexcitons) (formed of spatially separated electrons and holes) in a nanosystem that consists of ZnSe quantum dots synthesized in a borosilicate glass matrix is developed within the context of the modified effective mass approximation. It is shown that biexciton (exciton quasimolecule) formation is of the threshold character and possible in nanosystem, in with the spacing between the quantum dots surfaces is larger than a certain critical spacing. On the basis of analogy spectroscopy of electronic states of superatoms (or artificial atoms) and individual alkali metal atoms theoretically predicted a new artificial atom, which is similar to the new alkali metal atom.
Abstract: The theory of an exciton formed from spatially separated electron and hole (the hole is in the quantum dot volume, and the electron is localized at the outer spherical quantum dot–dielectric matrix interface) is developed within the modified effective mass method. The effect of significantly increasing the exciton binding energy in quantum dots of ...
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Optical Nonlinearity of Dielectric Nanocomposite
Vladimir P. Dzyuba,
Yurii N. Kulchin,
Sergey I. Pokutnyi
Issue:
Volume 3, Issue 6-1, November 2014
Pages:
22-37
Received:
9 July 2014
Accepted:
15 July 2014
Published:
31 July 2014
Abstract: In paper, being based upon the results of our works deals with experimental and theoretical studies of physical characteristics of nanoparticles responsible for specific optical properties of dielectric nanocomposites. During theoretical description and explanation of experimental data obtained, we considered nanoparticle as a multi-particle quantum system of charges which combines elements of quantum structures of a polyatomic molecule and a bulk crystal. Considering nanocomposites with quite a low concentration of nanoparticles (fractions of a percent), we didn’t take into account interparticle interaction.
Abstract: In paper, being based upon the results of our works deals with experimental and theoretical studies of physical characteristics of nanoparticles responsible for specific optical properties of dielectric nanocomposites. During theoretical description and explanation of experimental data obtained, we considered nanoparticle as a multi-particle quantu...
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Quasiatomic Nanoheterostructures: New Model Superatom in the Alkali - Metal Atoms
Sergey I. Pokutnyi,
Petr P. Gorbyk
Issue:
Volume 3, Issue 6-1, November 2014
Pages:
38-41
Received:
22 September 2014
Accepted:
6 October 2014
Published:
25 October 2014
Abstract: The theory of superatom (or artificial atom) formed from spatially separated electrons and holes (hole moving in the volume of a semiconductor (dielectric) quantum dot and an electron localized on the outer spherical interface between the quantum dot and a dielectric matrix) is developed. Predicted a new hydrogen - artificial atom, which is similar to the new alkali - metal atom.
Abstract: The theory of superatom (or artificial atom) formed from spatially separated electrons and holes (hole moving in the volume of a semiconductor (dielectric) quantum dot and an electron localized on the outer spherical interface between the quantum dot and a dielectric matrix) is developed. Predicted a new hydrogen - artificial atom, which is similar...
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Superatoms and Quasimolecules in Quasi-Zero-Dimensional Nanoheterostructures: Future Research
Sergey I. Pokutnyi,
Petr P. Gorbyk
Issue:
Volume 3, Issue 6-1, November 2014
Pages:
42-47
Received:
22 September 2014
Accepted:
6 October 2014
Published:
25 October 2014
Abstract: This review discusses the current state of research of artificial atoms (superatoms) (quasiatomic nanoheterostructures) and more complex nanostructures based on them - synthetic molecules, proposed a new model of an artificial atom, satisfactorily explaining its electronic properties, as well as the prospects for the development of the new scientific field.
Abstract: This review discusses the current state of research of artificial atoms (superatoms) (quasiatomic nanoheterostructures) and more complex nanostructures based on them - synthetic molecules, proposed a new model of an artificial atom, satisfactorily explaining its electronic properties, as well as the prospects for the development of the new scientif...
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Local Electron States in Ellipsoidal Nanosystems in Magnetic Field: Theory
Issue:
Volume 3, Issue 6-1, November 2014
Pages:
48-52
Received:
29 September 2014
Accepted:
5 October 2014
Published:
25 October 2014
Abstract: The influence of a homogeneous magnetic field on the electron states localized over the surface of an ellipsoidal semiconductor (dielectric) nanoparticle by the electrostatic image forces is studied theoretically. The effects of the resonant interaction of light with such local electron states in presence and in absence of a homogeneous magnetic field are investigated.
Abstract: The influence of a homogeneous magnetic field on the electron states localized over the surface of an ellipsoidal semiconductor (dielectric) nanoparticle by the electrostatic image forces is studied theoretically. The effects of the resonant interaction of light with such local electron states in presence and in absence of a homogeneous magnetic fi...
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Optical Absorption of One-Particle Quantum-Confined States of Charge Carriers in Quasi-Zero-Dimensional Nanogeterostructures: Theory
Issue:
Volume 3, Issue 6-1, November 2014
Pages:
53-56
Received:
22 September 2014
Accepted:
25 September 2014
Published:
25 October 2014
Abstract: A theory is developed for the interaction of an electromagnetic field with one-particle quantum-confined states of charge carriers in semiconductor quantum dots. It is shown that the oscillator strengths and dipole moments for the transitions involving one-particle states in quantum dots are gigantic parameters, exceeding the corresponding typical pa-rameters of bulk semiconductor materials. In the context of dipole approximation it is established that the gigantic optical absorption cross sections in the quasi-zero-dimensional systems make it possible to use the systems as efficient absorbing materials.
Abstract: A theory is developed for the interaction of an electromagnetic field with one-particle quantum-confined states of charge carriers in semiconductor quantum dots. It is shown that the oscillator strengths and dipole moments for the transitions involving one-particle states in quantum dots are gigantic parameters, exceeding the corresponding typical ...
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Size Quantization Stark Effect in Quantum Dots
Sergey I. Pokutnyi,
Oksana V. Naumenko
Issue:
Volume 3, Issue 6-1, November 2014
Pages:
57-60
Received:
29 September 2014
Accepted:
6 October 2014
Published:
25 October 2014
Abstract: Advantages of semiconductor quantum dots for study and diagnostics of biological nanosystems are discussed. A new method for amino acid diagnostics used semiconductor quantum dots is posed. Interaction of isolated quantum dots with charged amino acids is studied in detail. It is shown that such interaction results in a shift of the quantum dots luminescence spectra by several dozens of meV. This effect provides new possibilities for identification of biological nanoobjects using quantum dots.
Abstract: Advantages of semiconductor quantum dots for study and diagnostics of biological nanosystems are discussed. A new method for amino acid diagnostics used semiconductor quantum dots is posed. Interaction of isolated quantum dots with charged amino acids is studied in detail. It is shown that such interaction results in a shift of the quantum dots lum...
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