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Full-Text Articles in Physical Sciences and Mathematics
Theoretical Study Of The Mechanisms Of Absorption Of Semiconductor Spherical Quantum Dots In The Framework Of Quantum Mechanics, Kamoliddin Qoraboyev, Usmon Sapayev
Theoretical Study Of The Mechanisms Of Absorption Of Semiconductor Spherical Quantum Dots In The Framework Of Quantum Mechanics, Kamoliddin Qoraboyev, Usmon Sapayev
Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences
Analytical expressions for the linear and nonlinear optical susceptibilities of spherical quantum dots are obtained using the Schrödinger equation. To solve the Schrödinger equation, the Nikiforov-Uvarov method was used, assuming that electrons isolated in the medium are associated with the Gelman inverse quadratic potential. Using the density matrix formalism, analytical expressions were obtained for the coefficients of linear and nonlinear absorption and changes in the refractive index of quantum dots. Elements of the matrix of the electric dipole moment l=± 1 and m = 0 are obtained according to the selection rules. To demonstrate the results obtained, we used the …
Spectroscopic Investigation Of Defect-State Emission In Cdse Quantum Dots, Gülhan Güleroğlu, Caner Ünlü
Spectroscopic Investigation Of Defect-State Emission In Cdse Quantum Dots, Gülhan Güleroğlu, Caner Ünlü
Turkish Journal of Chemistry
CdSe quantum dots are the most studied Cd-based quantum dots with their high quantum yield, high photostability, narrow emission band, and easy synthesis procedure. They are frequently used to develop light emitting diode (LED) due to their unique photo¬physical properties; however, their narrow emission band causes a challenge to design white LEDs because white light emission requires emission in multiple wavelengths with broad emission bands. Here in this study, we developed CdSe quantum dots with a narrow band-edge emission band and broad defect-state emission band through a modified two-phase synthesis method. Our results revealed that defect-state emission is directly linked …
Novel "Turn Off-On" Sensors For Detection Of Dna-Acrylamide Interaction Using Zns Quantum Dots As A Phosphorescent Probe, Hayri̇ye Eda Şatana Kara
Novel "Turn Off-On" Sensors For Detection Of Dna-Acrylamide Interaction Using Zns Quantum Dots As A Phosphorescent Probe, Hayri̇ye Eda Şatana Kara
Turkish Journal of Chemistry
A novel "turn off-on" sensor for detection of interaction between DNA and acrylamide (ACR) was developed. In this method, L-cysteine capped Mn-doped ZnS quantum dots (QDs) were used as room temperature phosphorescent probes. In the ``turn-off'' mode, ACR was absorbed onto the surface of QDs via electrostatic interaction, which caused a quenching effect of room-temperature phosphorescence signal by photoinduced electron-transfer mechanism. ACR was removed from the QDs' surface with the addition of DNA. Thus, the phosphorescence emission of QDs was recovered and the system was turned to the ``turn-on'' mode. The quenching mechanism of QDs by ACR was collisional (dynamic) …
Current Development Of Quantum Dots Based Electrochemiluminescence Immunosensors, Ling-Ling Li, Qian Lu, Jun-Jie Zhu
Current Development Of Quantum Dots Based Electrochemiluminescence Immunosensors, Ling-Ling Li, Qian Lu, Jun-Jie Zhu
Journal of Electrochemistry
Electrochemiluminescence exhibits the merits of both luminescence and electrochemistry analysis, and has been extensively employed in biosensors. Quantum dots are considered one of the three main kinds of electrochemiluminescence luminophores due to their unique properties. This paper briefly reviews the classification and signal amplification technology of quantum dots based electrochemiluminescence immunosensors. Future research trends are also suggested.
The Influence Of Confinements On The Photon Flux Spectra In Amorphous Silicon Quantum Dots, Moafak Cadim Abdulrida, Nidhal Moosa Abdul-Ameer, Shatha Mohammad Abdul-Hakeem
The Influence Of Confinements On The Photon Flux Spectra In Amorphous Silicon Quantum Dots, Moafak Cadim Abdulrida, Nidhal Moosa Abdul-Ameer, Shatha Mohammad Abdul-Hakeem
Turkish Journal of Physics
We have theoretically calculated the photon flux of radiative recombination in amorphous silicon quantum dots (a-SiQDs) at room temperature. These quantum dots have been ranged in their diameter 1 to 4 nm. The convolution of probability density function of deepest energy states of conduction P_C(E) and valence P_V(E) bands within the capture volume was adopted. The behavior of this function can be classified into four regions according to the quantum dot size. The effect of spatial and quantum confinements on the peak value of photon flux must be taken into account. We found that a blue shift is classified by …
The Energy Spectrum Of Two-Electron Semiconductor Quantum Dots, Mohammad K. Elsaid
The Energy Spectrum Of Two-Electron Semiconductor Quantum Dots, Mohammad K. Elsaid
Turkish Journal of Physics
The ground-state properties of a two-dimensional quantum-dot are studied. We have used the shifted 1/N expansion method to solve the relative part Hamiltonian of two electrons confined in a quantum in the presence of an applied uniform magnetic field. The spin singlet-triplet transition in the ground state of the QD is shown. We have also displayed the singlet-triplet energy gap, J = \Delta = E_T - E_S, against the strength of the magnetic field for two electron quantum dot. Based on comparisons, the eigenenergies obtained by the shifted method are in excellent agreement with exact, variational, Hartree-Fock (HF) and Full-Configuration …
Self-Assembled Nano-Structures On The Icosahedral Al-Pd-Mn Quasicrystal, Mehmet Erbudak, Jean-Nicolas Longchamp, Yves Weisskopf
Self-Assembled Nano-Structures On The Icosahedral Al-Pd-Mn Quasicrystal, Mehmet Erbudak, Jean-Nicolas Longchamp, Yves Weisskopf
Turkish Journal of Physics
A quasicrystal is a solid with an aperiodic atomic distribution, but displaying discrete diffraction pattern. At an interface where an ordinary crystal and a quasicrystal intersect, the lack of commensurability between the structures leads to misfits on atomic scale resulting in a wealth of novelties. Here, we present experimental observations on three essentially different cases: Al, Fe, and Si ultra-thin layers grown in vacuum on the pentagonal surface of an icosahedral Al-Pd-Mn quasicrystal. In all three cases, the growing layer decays into nm-size islands. Al is the major alloy component of the substrate material and provides a natural tool to …
Phase Measurements In Aharonov-Bohm Interferometers, Amnon Aharony, Ora Entin-Wohlman, Yoseph Imry
Phase Measurements In Aharonov-Bohm Interferometers, Amnon Aharony, Ora Entin-Wohlman, Yoseph Imry
Turkish Journal of Physics
In this paper we address measurements of the resonant quantum transmission amplitude t_{QD} = -i t_{QD} e^{i\alpha_{QD}} through a quantum dot (QD), as function of the plunger gate voltage V. Mesoscopic solid state Aharonov-Bohm interferometers (ABI) have been used to measure the ``intrinsic" phase, \alpha_{QD}, when the QD is placed on one of the paths. In a ``closed" interferometer, connected to two terminals, the electron current is conserved, and Onsager's relations require that the conductance G through the ABI is an even function of the magnetic flux \Phi = \hbar c\phi/e threading the ABI ring. Therefore, if one fits G …