Electronic and optical properties ofSi∕SiO2nanostructures. II. Electron-hole recombination at theSi∕SiO2quantum-well–quantum-dot transition

2005 ◽  
Vol 72 (20) ◽  
Author(s):  
N. Pauc ◽  
V. Calvo ◽  
J. Eymery ◽  
F. Fournel ◽  
N. Magnea
Keyword(s):  
Optical Properties ◽  
Quantum Dot ◽  
Electron Hole ◽  
Electronic And Optical Properties ◽  
Hole Recombination

Optically Detected Magnetic Resonance and Double Beam Photoluminescence of CdS/HgS/CdS Nanoparticles

1998 ◽  
Vol 536 ◽  
Author(s):  
H. Porteanu ◽  
A. Glozman ◽  
E. Lifshitz ◽  
A. Eychmüller ◽  
H. Weller
Keyword(s):  
Optical Properties ◽  
Magnetic Resonance ◽  
Cds Nanoparticles ◽  
Electron Hole ◽  
Cladding Layer ◽  
Double Beam ◽  
Optically Detected Magnetic Resonance ◽  
Optically Detected ◽  
Cladding Layers ◽  
Hole Recombination

AbstractCdS/HgS/CdS nanoparticles consist of a CdS core, epitaxially covered by one or two monolayers of HgS and additional cladding layers of CdS. The present paper describes our efforts to identify the influence of CdS/HgS/CdS interfaces on the localization of the photogenerated carriers deduced from the magneto-optical properties of the materials. These were investigated by the utilization of optically detected magnetic resonance (ODMR) and double-beam photoluminescence spectroscopy. A photoluminescence (PL) spectrum of the studied material, consists of a dominant exciton located at the HgS layer, and additional non-excitonic band, presumably corresponding to the recombination of trapped carriers at the interface. The latter band can be attenuated using an additional red excitation. The ODMR measurements show the existence of two kinds of electron-hole recombination. These electron-hole pairs maybe trapped either at a twin packing of a CdS/HgS interface, or at an edge dislocation of an epitaxial HgS or a CdS cladding layer.

scholarly journals Tunable electronic and optical properties of a BAs/As heterostructure by vertical strain and external electric field

RSC Advances ◽  
2021 ◽  
Vol 11 (35) ◽  
pp. 21824-21831
Author(s):  
X. Q. Deng ◽  
R. Q. Sheng ◽  
Q. Jing
Keyword(s):  
Optical Properties ◽  
Electric Field ◽  
External Electric Field ◽  
Photogenerated Electron ◽  
Electron Hole ◽  
Electronic And Optical Properties ◽  
Vertical Strain

The CBM (VBM) of the heterostructure is mainly contributed by the BAs (arsenene), which will favor the separation of photogenerated electron–hole pairs.

The Effect of Chromium on the Optical Properties and Photoactivity of Nano-Particulate Rutile

2012 ◽  
Vol 554-556 ◽  
pp. 502-506 ◽  
Author(s):  
Li Wei Wang ◽  
Terry A. Egerton
Keyword(s):  
Optical Properties ◽  
Photocatalytic Activity ◽  
Reflectance Spectroscopy ◽  
Electron Trapping ◽  
Electron Hole ◽  
High Chromium ◽  
Chromium Doping ◽  
Chromium Addition ◽  
Co Precipitation ◽  
Hole Recombination

Chromium doped rutile TiO2was synthesized by either co-precipitation or impregnation (surface-doping) and characterized by XRD and reflectance spectroscopy. Chromium addition did not change the TiO2structure nor did the structure of the co-precipitated products differ from that of the impregnated samples. However, chromium doping moved the absorption of both sets of products into the visible and significantly affected the TiO2photocatalytic activity for isopropanol (IPA) oxidation. At high chromium concentrations the photoactivity of the co-precipitated samples was reduced by a larger amount than that of the impregnated samples; this was attributed to a higher concentration of Cr3+ions in the rutile lattice. Unexpectedly, increased photoactivity was measured for low Cr levels of surface-doped rutile. This may be caused by increased electron-trapping, at surface Cr6+ions, and correspondingly reduced, electron-hole recombination.

Quantum-Dot Molecules for Potential Applications in Terahertz Devices

2004 ◽  
Vol 829 ◽  
Author(s):  
Valeria Gabriela Stoleru ◽  
Elias Towe ◽  
Chaoying Ni ◽  
Debdas Pal
Keyword(s):  
Optical Properties ◽  
Quantum Dot ◽  
Strain Field ◽  
Strain Distribution ◽  
Major Step ◽  
Cross Sectional ◽  
Electronic And Optical Properties ◽  
Quantum Dot Molecules ◽  
Transmission Electron ◽  
Potential Applications

ABSTRACTThe experimental and theoretical results of the electronic and optical properties of quantum dot artificial molecules (AMs), formed by pairs of electronically coupled quantum dots (QDs), are presented here in order to identify the necessary conditions for the development of new types of terahertz (THz) injection lasers based on intraband carrier transitions. We have performed analytical calculations to obtain the spatial strain distribution in vertically aligned (In, Ga)As QDs grown on (001) GaAs substrates by molecular beam epitaxy. Electronic coupling of the dots, mainly governed by the thickness of the separating barrier between the dot layers, is allowed due to the strain field-assisted self-organization of the dots. The calculated strain field reproduces our cross sectional high-resolution transmission electron microscopy observations very well. We further take into account the microscopic effects of the spatial strain distribution on carrier confinement potentials, and compute the electronic structure of the AM. Our calculations of the peak luminescence energies are in good agreement with our experimental results and those of others. The growth of quantum dot molecules represents a major step in tailoring the electronic and optical properties of the nanostructures.

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