scholarly journals Ultrafast optical properties of type-II CdZnS/ZnSe core-shell quantum dots

2018 ◽  
Vol 26 (14) ◽  
pp. 18480 ◽  
Author(s):  
Lingling Ran ◽  
Haiyang Li ◽  
Wenzhi Wu ◽  
Yachen Gao ◽  
Zhijun Chai ◽  
...  
2017 ◽  
Vol 6 (1) ◽  
pp. 80-86
Author(s):  
S. N. Saravanamoorthy ◽  
A. John Peter

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.


2017 ◽  
Vol 90 (1) ◽  
pp. 52-58 ◽  
Author(s):  
Taichi Watanabe ◽  
Kohji Takahashi ◽  
Kunio Shimura ◽  
Hang-Beom Bu ◽  
Kim Hyeon-Deuk ◽  
...  

Author(s):  
Nguyen Xuan Ca ◽  
Nguyen Thi Hien

The CdSe, type-II CdSe/CdTe core/shell and type-II/type-I CdSe/CdTe/ZnS core/shell/shell  quantum dots (QDs) were successfully synthesized in a noncoordinating solvent. The phonon characterizations, optical properties and structures of the synthesized QDs were characterized by Raman scattering (RS) spectra, photoluminescence (PL) spectroscopy, PL-decay lifetime, absorption spectroscopy (Abs), and X-ray diffraction (XRD). The growth of QDs was monitored by using RS, which demonstrated the formation of correct of the core/shell and core/shell/shell structures. Observation results from XRD reveal that all QDs crystallize in the cubic phase with zinc-blende structure. The typical characteristics of spatially indirect recombination for type-II QDs were observed through Abs and PL spectroscopy. The ZnS shell significantly enhanced the PL quantum yeild (QY), the optical durability, the chemical stability and separating CdSe/CdTe QDs from the surroundings. The effect of excitation power on the PL properties of the CdSe core,  CdSe/CdTe and CdSe/CdTe/ZnS QDs has been investigated.


2008 ◽  
Vol 112 (23) ◽  
pp. 8587-8593 ◽  
Author(s):  
Qinghui Zeng ◽  
Xianggui Kong ◽  
Yajuan Sun ◽  
Youlin Zhang ◽  
Langping Tu ◽  
...  

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 39 ◽  
pp. 46-51 ◽  
Author(s):  
S. Mathew ◽  
Bishwajeet Singh Bhardwaj ◽  
Amit D. Saran ◽  
P. Radhakrishnan ◽  
V.P.N. Nampoori ◽  
...  

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