Influence of electron-hole recombination on optical properties of boro-silicate glasses containing CdS quantum dots

2017 ◽  
Vol 181 ◽  
pp. 367-373 ◽  
Author(s):  
S.R. Munishwar ◽  
P.P. Pawar ◽  
R.S. Gedam
1998 ◽  
Vol 536 ◽  
Author(s):  
H. Porteanu ◽  
A. Glozman ◽  
E. Lifshitz ◽  
A. Eychmüller ◽  
H. Weller

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.


RSC Advances ◽  
2021 ◽  
Vol 11 (14) ◽  
pp. 7961-7971
Author(s):  
N. D. Vinh ◽  
P. M. Tan ◽  
P. V. Do ◽  
S. Bharti ◽  
V. X. Hoa ◽  
...  

The role of samarium (Sm) dopant on the structural, morphological, and optical properties of CdS QDs and CdS/ZnS core/shell QDs was methodically reported.


2015 ◽  
Vol 3 (15) ◽  
pp. 3745-3751 ◽  
Author(s):  
Yu Cang ◽  
Rui Zhang ◽  
Guixin Shi ◽  
Jianchao Zhang ◽  
Lixiao Liu ◽  
...  

The SPB@CdS nanoparticles exhibit controllable and reversible photoluminescence with pH as a trigger and strong photochemical stability in basic solution.


1996 ◽  
Vol 31 (2) ◽  
pp. 423-430 ◽  
Author(s):  
T. Takada ◽  
J. D. Mackenzie ◽  
M. Yamane ◽  
K. Kang ◽  
N. Peyghambarian ◽  
...  

2018 ◽  
Vol 59 (4) ◽  
pp. 870-876 ◽  
Author(s):  
O. V. Sedelnikova ◽  
C. P. Ewels ◽  
L. G. Bulusheva ◽  
A. V. Okotrub

2006 ◽  
Vol 14 (17) ◽  
pp. 7994 ◽  
Author(s):  
Koo-Chul Je ◽  
Honglyoul Ju ◽  
Mona Treguer ◽  
Thierry Cardinal ◽  
Seung-Han Park

2012 ◽  
Vol 554-556 ◽  
pp. 502-506 ◽  
Author(s):  
Li Wei Wang ◽  
Terry A. Egerton

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.


1992 ◽  
Vol 01 (01) ◽  
pp. 25-50 ◽  
Author(s):  
V. ESCH ◽  
K. KANG ◽  
B. FLUEGEL ◽  
Y.Z. HU ◽  
G. KHITROVA ◽  
...  

We summarize the linear and nonlinear optical properties of a variety of CdTe and CdS quantum dots in glass. The measured linear absorption of the CdTe sample is compared with calculations involving valence-band mixing due to the quantum confinement. The temperature dependence of the lowest quantum-confined transition and its linewidth for samples with various crystallite sizes are measured and compared with a simple model. It is found that the shift of the energetically lowest quantum-confined transition as a function of temperature is the same as the temperature-dependent band-gap reduction in bulk materials. Excitation of the sample with pulses ranging from femtoseconds to microseconds allows distinguishing between various mechanisms responsible for the observed optical nonlinearities. At very early times, phase-space filling and Coulomb interaction between the excited charged carriers are responsible for the absorption changes. At later times, Coulomb effects due to “trapped” carriers remain and last for nanoseconds or microseconds.


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