Reducing Blinking in Small Core–Multishell Quantum Dots by Carefully Balancing Confinement Potential and Induced Lattice Strain: The “Goldilocks” Effect

ACS Nano ◽  
2016 ◽  
Vol 10 (4) ◽  
pp. 4072-4082 ◽  
Author(s):  
Benard Omogo ◽  
Feng Gao ◽  
Pooja Bajwa ◽  
Mizuho Kaneko ◽  
Colin D. Heyes
Keyword(s):  
Quantum Dots ◽  
Lattice Strain ◽  
Small Core ◽  
Confinement Potential

scholarly journals Shell-Filling Effects in Circular Quantum Dots

VLSI Design ◽  
1998 ◽  
Vol 8 (1-4) ◽  
pp. 443-447 ◽  
Author(s):  
M. Macucci ◽  
Karl Hess
Keyword(s):  
Quantum Dots ◽  
Quantum Dot ◽  
Confinement Potential

We investigate the dependence of the capacitive energy associated with a circular quantum dot on the number of electrons in the dot and on the parameters defining the potential confinement. Our results reproduce the shell-filling behavior that has recently been experimentally observed and allow us to estimate the shape of the confinement potential and the dot size of the experiments.

Electrostatic quantum dots with designed shape of confinement potential

2003 ◽  
Vol 17 ◽  
pp. 494-497 ◽  
Author(s):  
K. Lis ◽  
S. Bednarek ◽  
B. Szafran ◽  
J. Adamowski
Keyword(s):  
Quantum Dots ◽  
Confinement Potential

scholarly journals Modeling of circular quantum dots localized in double heterostructures

2021 ◽  
Vol 65 (1) ◽  
pp. 33-39
Author(s):  
V. V. Kudryashov ◽  
A. V. Baran
Keyword(s):  
Quantum Dots ◽  
Energy Spectrum ◽  
Energy Levels ◽  
Finite Depth ◽  
Wave Functions ◽  
Axially Symmetric ◽  
Confinement Potential ◽  
Double Heterostructures ◽  
New Type ◽  
Potential Parameters

The circular quantum dots localized in the double heterostructures are simulated by means of the axially symmetric smooth confinement potential of finite depth. For the proposed potential of new type, the exact wave functions and the energy levels of electron are found. The dependence of energy spectrum on potential parameters is investigated.

Effects of Confinement on Shallow Impurities in GaAs-Ga 1−xA1xAs Quantum Dots

1992 ◽  
Vol 281 ◽  
Author(s):  
Francisco A. P. Osörio ◽  
Oscar HipöLito ◽  
Francois M. Peeters
Keyword(s):  
Magnetic Field ◽  
Quantum Dots ◽  
Quantum Dot ◽  
Ground State Energy ◽  
Ground State ◽  
State Energy ◽  
Perpendicular Magnetic Field ◽  
Confinement Potential ◽  
Shallow Impurity ◽  
Shallow Impurities

ABSTRACTThe ground state energy of a shallow impurity placed in the center of a circular quantum dot is studied. The effects of the strength of the confinement potential and a perpendicular magnetic field are investigated theoretically.

Electron Energy Spectra of Single and Multiple AlGaN/GaN Quantum Dots with Spontaneous and Piezoelectric Polarization Effects

2007 ◽  
Vol 1017 ◽  
Author(s):  
Choudhury Jayant Praharaj
Keyword(s):  
Quantum Dots ◽  
Gallium Nitride ◽  
Bound States ◽  
Algan Layer ◽  
Coupled Quantum Dots ◽  
Aluminium Concentration ◽  
Polarization Effects ◽  
Confinement Potential ◽  
Piezoelectric Polarization ◽  
Wide Range

AbstractWe present numerical calculations of electron spectra of single and multiple coupled quantum dots based on Aluminium Gallium Nitride / Gallium Nitride heterostructures. The effect of spontaneous and piezoelectric polarization on the confinement potential seen by the electrons is taken into account through bound interface sheet charges. We also calculated the spectra without polarization effects for reference. For some quantum dot dimensions, the energy eigenvalues shift by several hundred meVs due to the polarization charges. We calculate the spectra for the two cases of box-shaped and cylindrical quantum dots. The latter case is an approximation to quantum dots with hexagonal-facet shapes recently reported in the literature. The quantum dots in our calculations are surrounded by vacuum in the lateral direction, but the same qualitative conclusions will hold if the dots are embedded in some material, as long as the barrier heights are large. For GaN vertical confinement of less than 30 angstroms, most of the bound states are associated with the lowest eigenvalue of the vertical confinement potential. This is also true for higher vertical confinement dimensions because the triangular potential seen by the electrons is the same for the lowest energy eigenstates. The electric field in the vertical direction is a strong function of the aluminium concentration in the AlGaN layer. As the AlGaN layer composition is varied from very high Al concentration to medium Al concentration, the spectra shift by several hundred meVs, referred to the onset of the continuous spectra. The transition frequencies between bound states and between bound and the lowest continuum states lie in the low to the high infra-red range, and can be varied over a wide range by both the dimensions and the barrier aluminium concentration. For the case of 4 coupled quantum dots formed by repeated AlGaN/GaN heterojunctions, we find that the polarization-induced electric fields lead to excessive band-bending and as a consequence there are fewer bound states compared to the spectrum calculated without polarization effects.

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