QUANTUM SIZE EFFECTS ON THE ENERGY LEVELS AND FAR-INFRARED SPECTRA: CHANGES FROM QUANTUM DOTS TO QUANTUM RINGS

2007 ◽  
Vol 21 (27) ◽  
pp. 4715-4724
Author(s):  
HUI PAN

The energy levels and far-infrared spectra of two electrons confined in quantum dots and quantum rings under a magnetic field have been investigated. The size and shape effects of quantum rings on the levels and the spectra are clearly revealed. It is found that the spin oscillation of two electrons in a quantum ring with a magnetic field is caused by the Coulomb interaction. The transitions of two-electron far-infrared spectra are clearly shown from quantum dots to quantum rings. The influence of electron–electron interaction on the energy levels and far-infrared spectra has been discussed. The quantum size effects predict a possibility to observe phenomena related to electron-electron interaction in quantum rings.

2020 ◽  
Vol 13 (06) ◽  
pp. 2051036
Author(s):  
Junjie Zhang ◽  
Hujiabudula Maimaitizi ◽  
Tao Zhang ◽  
Yalkunjan Tursun ◽  
Dilinuer Talifu ◽  
...  

In this work, a facile ultrasonic method for the fabrication of AgCl quantum dots (AgCl QDs) with an average diameter of about 2.5[Formula: see text]nm was reported for the first time. The material was analyzed by various techniques. In addition, effects of material’s size on its photocatalytic activities were studied. Results suggested that the AgCl QDs exhibited excellent photocatalytic activity to degrade Rhodamine B (RhB) and tetracycline (TC) under visible light illumination, and the degradation rate of RhB (TC) had reached up to 96.6% (72.2%) in 20 min, which was higher than that of AgCl nanoparticles (23[Formula: see text]nm) and AgCl nanospheres (114[Formula: see text]nm), respectively. Besides, the band gap of the material was increased when the size of material decreased from 23[Formula: see text]nm to 2.5[Formula: see text]nm. The significantly improved photocatalytic performance and increased band gap of AgCl QDs were mainly related to the quantum size effects of AgCl, which results in the more electron fluctuation in quantized energy levels and the lower recombination of electrons and holes.


2002 ◽  
Vol 16 (27) ◽  
pp. 4093-4103 ◽  
Author(s):  
S. BASKOUTAS ◽  
M. RIETH ◽  
A. F. TERZIS ◽  
V. KAPAKLIS ◽  
C. POLITIS

Studying the quantum size effects on the exciton energy of two-dimensional CdS quantum dots in the single band effective mass approximation for both electron and hole, we use a finite confinement in the x–y plane and we assume also that the induced charge is spread along a very thin interface in the z-direction. Solving the Schrödinger equation with a new numerical method, which is called potential morphing method, we obtain the corresponding energy within the self-consistent Hartree scheme. Excellent agreement is obtained with the experimental values of exciton energies for various sizes of CdS quantum dots in the strong, medium and weak confinement limit.


2006 ◽  
Vol 88 (10) ◽  
pp. 103114 ◽  
Author(s):  
T. W. Cornelius ◽  
M. E. Toimil-Molares ◽  
R. Neumann ◽  
G. Fahsold ◽  
R. Lovrincic ◽  
...  

2014 ◽  
Author(s):  
W. Gutiérrez ◽  
L. F. García ◽  
I. D. Mikhailov

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