scholarly journals Strong Quantum Confined Lead Sulphide Quantum Dots using Ionic Reaction and Their Properties

2019 ◽  
Author(s):  
Vikram P. Bhalekar ◽  
◽  
Habib M. Pathan ◽  
Keyword(s):  
Quantum Dots ◽  
Lead Sulphide ◽  
Ionic Reaction ◽  
Quantum Confined

OPTICAL PROPERTIES OF CdTe AND CdS QUANTUM DOTS IN GLASS

1992 ◽  
Vol 01 (01) ◽  
pp. 25-50 ◽  
Author(s):  
V. ESCH ◽  
K. KANG ◽  
B. FLUEGEL ◽  
Y.Z. HU ◽  
G. KHITROVA ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Optical Nonlinearities ◽  
Cds Quantum Dots ◽  
Temperature Dependent ◽  
Linear Absorption ◽  
Crystallite Sizes ◽  
Band Mixing ◽  
Quantum Confined ◽  
Coulomb Effects

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.

Quantum-confined Franz-Keldysh effect in CdTe quantum dots in glass

Optics News ◽  
1989 ◽  
Vol 15 (12) ◽  
pp. 26 ◽  
Author(s):  
V. Esch ◽  
G. Khitrova ◽  
H. M. Gibbs ◽  
Xu Jiajin ◽  
L. C. Liu ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Cdte Quantum Dots ◽  
Quantum Confined ◽  
Franz Keldysh Effect

scholarly journals A top–down strategy towards monodisperse colloidal lead sulphide quantum dots

2013 ◽  
Vol 4 (1) ◽  
Author(s):  
Jing Yang ◽  
Tao Ling ◽  
Wen-Tian Wu ◽  
Hui Liu ◽  
Min-Rui Gao ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Top Down ◽  
Lead Sulphide ◽  
Colloidal Lead

scholarly journals Manipulating quantum-confined Stark shift in electroluminescence from quantum dots with side gates

2008 ◽  
Vol 10 (5) ◽  
pp. 053036 ◽  
Author(s):  
Xiulai Xu ◽  
Aleksey Andreev ◽  
David A Williams
Keyword(s):  
Quantum Dots ◽  
Stark Shift ◽  
Quantum Confined

scholarly journals Quantum Confinement Effect and Photoenhancement of Photoluminescence of PbS and PbS/MnS Quantum Dots

2020 ◽  
Vol 10 (18) ◽  
pp. 6282
Author(s):  
Muhammad Safwan Zaini ◽  
Josephine Ying Chyi Liew ◽  
Shahrul Ainliah Alang Ahmad ◽  
Abdul Rahman Mohmad ◽  
Mazliana Ahmad Kamarudin
Keyword(s):  
Aqueous Solution ◽  
Quantum Dots ◽  
Quantum Confinement ◽  
Shell Thickness ◽  
Quantum Confinement Effect ◽  
Band Gap Energy ◽  
Confinement Effect ◽  
Core Shell ◽  
Lead Sulphide ◽  
Peak Energy

The quantum confinement effect and photoenhancement of photoluminescence (PL) of lead sulphide (PbS) quantum dots (QDs) and lead sulphide/manganese sulphide (PbS/MnS) core shell QDs capped with thiol ligands in aqueous solution were investigated. From PL results, the presence of MnS shells gives a strong confinement effect which translates to higher emission energy in PbS/MnS core shell QDs. Increasing MnS shell thickness from 0.3 to 1.5 monolayers (ML) causes a blueshift of PL peak energies as the charge carriers concentrated in the PbS core region. Enhancement of the PL intensity of colloidal PbS and PbS/MnS core shell QDs has been observed when the samples are illuminated above the band gap energy, under continuous irradiation for 40 min. Luminescence from PbS QDs and PbS/MnS core shell QDs can be strongly influenced by the interaction of water molecules and oxygen present in aqueous solution adsorbed on the QD surface. However, PbS/MnS core shell QDs with a shell thickness of 1.5 ML did not show a PL peak energy stability as it was redshifted after 25 min, probably due to wider size distribution of the QDs.

Reply to Comment on ‘Unconventional gap state of trapped exciton in lead sulphide quantum dots’

2011 ◽  
Vol 22 (23) ◽  
pp. 238002 ◽  
Author(s):  
J E Lewis ◽  
S Wu ◽  
Xiaomei Jiang
Keyword(s):  
Quantum Dots ◽  
Lead Sulphide ◽  
Gap State
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