Excited states of an electron-hole pair in spherical quantum dots and their optical properties

2002 ◽  
Vol 65 (16) ◽  
Author(s):  
Takayuki Uozumi ◽  
Yosuke Kayanuma
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Excited States ◽  
Hole Pair ◽  
Electron Hole ◽  
Electron Hole Pair

Interband Optical Transition Energies in Type-II PbSe/PbS Core/Shell Quantum Dots

2017 ◽  
Vol 6 (1) ◽  
pp. 80-86
Author(s):  
S. N. Saravanamoorthy ◽  
A. John Peter
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Shell Thickness ◽  
Optical Transition ◽  
Hole Pair ◽  
Core Shell ◽  
Type Ii ◽  
Electron Hole ◽  
Transition Energies ◽  
Electron Hole Pair

Electronic and optical properties of Type-II lead based core/shell semiconducting quantum dots are reported. Binding energies of electron–hole pair, optical transition energies and the absorption coefficients are investigated taking into account the geometrical confinement in PbSe/PbS core/shell quantum dot nanostructure. The energies are obtained with the increase of shell thickness for various inner core radii. The probability densities of electron and hole wave functions of radial coordinate of the core PbSe and PbS shell quantum dots are presented. The optical transition energy with the spatial confinement is brought out. The electronic properties are obtained using variational approach whereas the compact density matrix method is employed for the nonlinear optical properties. The results show that (i) a decrease in binding energy is obtained when the shell thickness increases due to more separation of electron–hole pair and (ii) the energy band gap decreases with the increase in the shell thickness resulting in the reduction of the higher energy interband transitions.

Homogeneous linewidth of confined electron-hole-pair states in II-VI quantum dots

1993 ◽  
Vol 47 (7) ◽  
pp. 3684-3689 ◽  
Author(s):  
U. Woggon ◽  
S. Gaponenko ◽  
W. Langbein ◽  
A. Uhrig ◽  
C. Klingshirn
Keyword(s):  
Quantum Dots ◽  
Hole Pair ◽  
Electron Hole ◽  
Electron Hole Pair ◽  
Homogeneous Linewidth

Photoluminescence from vibrational excited-states for organic molecules adsorbed on Si nanoparticles

2017 ◽  
Vol 19 (32) ◽  
pp. 21856-21861 ◽  
Author(s):  
M. Maeda ◽  
T. Matsumoto ◽  
H. Kobayashi
Keyword(s):  
Excited States ◽  
Organic Molecules ◽  
Hole Pair ◽  
Electron Hole ◽  
Si Nanoparticles ◽  
Electron Hole Pair

PL mechanism involving transfer of an electron–hole pair generated in Si nanoparticles to adsorbed DMA.

Electron-Hole Pair Relaxation Dynamics in Binary Copper-Based Semiconductor Quantum Dots

2005 ◽  
Vol 152 (6) ◽  
pp. G427 ◽  
Author(s):  
Yongbing Lou ◽  
Ming Yin ◽  
Stephen O’Brien ◽  
Clemens Burda
Keyword(s):  
Quantum Dots ◽  
Semiconductor Quantum Dots ◽  
Hole Pair ◽  
Relaxation Dynamics ◽  
Electron Hole ◽  
Electron Hole Pair

Investigation of Two-Electron-Hole Pair Resonances in Semiconductor Quantum Dots

1991 ◽  
pp. 289-295
Author(s):  
N. Peyghambarian ◽  
B. P. McGinnis ◽  
K. I. Kang ◽  
Sandalphon ◽  
S. W. Koch ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Semiconductor Quantum Dots ◽  
Hole Pair ◽  
Electron Hole ◽  
Electron Hole Pair

Synthesis and Photocatalytic Degradation Performance of g-C3N4/ CQDs/SAPO-5 Ternary Composite

2018 ◽  
Vol 768 ◽  
pp. 201-205 ◽  
Author(s):  
Ling Fang Qiu ◽  
Zhi Wei Zhou ◽  
Xiao Bin Qiu ◽  
Shu Wang Duo
Keyword(s):  
Quantum Dots ◽  
Photocatalytic Activity ◽  
Recombination Rate ◽  
Load Ratio ◽  
Carbon Quantum Dots ◽  
Hole Pair ◽  
Electron Hole ◽  
Ternary Composite ◽  
Electron Hole Pair ◽  
Ft Ir

Due to the fatal drawback of fast photoreduced electron-hole pair recombination rate of g-C3N4, g-C3N4/CQDs/SAPO-5 ternary composite were prepared. Both of carbon quantum dots and SAPO-5 can form heterojunction with g-C3N4to inhibit the recombination. Their properties were characterized by XRD, SEM, FT-IR, DRS and PL. Data of PL shows a much lower photoreduced electron-hole pair recombination rate of g-C3N4/CQDs/SAPO-5. The effect of CQDs amount loaded on ternary composite on the RhB photodegradation performance under visible light was discussed in detail. The observed RhB degradation performances indicate that the order of photocatalytic activity is: g-C3N4/CQDs/SAPO-5> g-C3N4/ SAPO-5 > g-C3N4. g-C3N4/CQDs/SAPO-5 with CQDs load ratio of 0.25 w.t.% shows the best photodegradation performance. The highest efficiency is about 24.43% higher than g-C3N4/ SAPO-5 and 47.15% higher than pristine g-C3N4, respectively. This work is promising for developing novel g-C3N4-based photocatalysts for environmental purification.

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