Results 241 to 250 of about 177,744 (299)

Triskelion Structured Colloidal Quantum Dots

The Journal of Physical Chemistry A, 2021
We show, using density functional theory and ab initio molecular dynamics, that certain small colloidal quantum dots with a mixed nanocrystal core capped with achiral surface ligands spontaneously form a triskelion (from the Greek, three-legged) structure with (approximate) C3 symmetry that can be dynamically stable at room temperature when ...
Richard D. Edwards, Harold P. Hodgins, Ian P. Hamilton   +2 more
openaire   +2 more sources

Electronic structure of quantum dots

Reviews of Modern Physics, 2002
The properties of quasi-two-dimensional semiconductor quantum dots are reviewed. Experimental techniques for measuring the electronic shell structure and the effect of magnetic fields are briefly described. The electronic structure is analyzed in terms of simple single-particle models, density-functional theory, and "exact" diagonalization methods. The
Reimann,Stephanie M., Manninen, Matti
openaire   +2 more sources

Electronic structure of ellipsoidally deformed quantum dots

Journal of Physics: Condensed Matter, 2001
Using a three-dimensional local spin-density functional method, we investigate the electronic structure of quasi two-dimensional ellipsoidal quantum dots with elliptical deformation. Changes in the electron addition energy spectra and spin polarization are investigated as a function of the number of electrons and the elliptical deformation on the ...
Lee, IH, Kim, YH Kim, Yong-Hoon, Ahn, KH
openaire   +2 more sources

Quantum dots in quantum well structures

Journal of Luminescence, 1996
Abstract Recent progress toward fabricating and characterizing quantum dots in III–V quantum well structures is reviewed. Quantum dots made by use of lithography and etching, including deep-etched, barrier-modulated, strain-induced and interdiffused quantum dots, are described.
openaire   +1 more source

Hot-electron bistability in quantum-dot structures

Physical Review B, 1993
We present a theoretical analysis of hot-electron bistability in quantum-dot structures. An energy balance approach is used to demonstrate the existence of negative differential conductance due to thermal runaway of the carriers in the dot structure.
, Goodnick, , Wu, , Wybourne, , Smith
openaire   +2 more sources

Excitons in Quantum-Dot Quantum Well Structures

2000
The energy levels and excitation spectra of multi-shell nanocrystals composed of ZnS and CdS layers are investigated. The calculations are performed both in the 6-band envelope function approximation and in the tight-binding approach. Charge separation of pair states, with the electron and hole in different layers, is observed in a number of structures.
W. Jaskólski, Garnett W. Bryant
openaire   +1 more source

Electronic Structures of InN/GaN Quantum Dots

Journal of Nanoscience and Nanotechnology, 2009
In this letter, ab-initio calculations are performed to study the electronic structures of the InN quantum dot embedded in the GaN matrix. By analyzing the site-decomposed densities of states, an anisotropic potential well in the dot region is clearly depicted.
Chen, S. S., Lin, W., Li, S. P., Kang, J. Y.   +3 more
openaire   +3 more sources

Coupled quantum dot–ring structures by droplet epitaxy

Nanotechnology, 2011
The fabrication, by pure self-assembly, of GaAs/AlGaAs dot-ring quantum nanostructures is presented. The growth is performed via droplet epitaxy, which allows for the fine control, through As flux and substrate temperature, of the crystallization kinetics of nanometer scale metallic Ga reservoirs deposited on the surface.
SOMASCHINI, CLAUDIO, BIETTI, SERGIO, Koguchi, N, SANGUINETTI, STEFANO   +3 more
openaire   +3 more sources