Synthesis of Nano CdS by Pulsed Laser Ablation in Liquid Environment (PLAL) A.
a Darwish ,
W.
a Eisa ,
A.
a Shabaka ,
M.
b Talaat
a Spectroscopy Department, Physics Division, National Research Center, Dokki, Cairo, Egypt b Physics Department, Faculty of Science, Ain Shams University, Cairo, Egypt
Introduction
Results and discussions
Societal Impacts
UV-visible spectra of nano CdS at a different medium
Many attempts have been made by the researchers in the world to discover and develop the new synthesis methods and characterization techniques to control shape and size of nanostructures due to the heavily shape/sizedependent functional properties .
Nanotechnology Revolution
Industrial Revolutions
Time Fig.1: The impacts of nanotechnology revolution and industrial revolution
• PLAL, one of the newest techniques, offers an alternative method for synthetic nanostructures as compared to the other methods which is based on the Pulsed laser Ablation technique (PLA).
Fig.8: Controlling of the suitable medium (Deionized water, Distilled water, and Tap water) of PLAL process
UV-vis, TEM & XRD of nano CdS
Bottom-Up technique
Femto Second
Focuses on the developing a novel way to synthesize nanostructures with different shape/size by using Pulsed Laser technique to be applicable in optoelectronic and solar cell applications.
Experimental work Synthesis of CdS Nanostructures
Fig.9: TEM & UV-vis spectra of the produced nano CdS in case of Ns, Ps, Fs laser by using Top-Down technique
Bottom-Up technique
Deionized water
CdCl2 solution
Cd+2 Cd+2
S-2
CdS
CdS-tablet
S-tablet
Before PLAL
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After PLAL
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CdS
Cd+2 Cd+2
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Fig.10: TEM & UV-vis spectra of nano CdS in case of Ns by using Top-Down technique
Top-Down techniques
S-2
Cd+2
Nano Second
Aim of work
Nano Second
Fig.2: Mechanism of Pulsed Laser Ablation process (PLA)
Pico Second
• Dynamic of PLA: Photons generate electrons - Electron avalanche - Plasma expansion - Material is ejected.
Top-Down techniques
Before PLAL
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Mirror
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Fig.12:XRD pattern of nano CdS prepared by PLAL (TopDown technique)
After PLAL
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Fig.11: XRD pattern of nano CdS prepared by PLAL (BottomUp technique)
Laser source
Laser source
Future work ISA, We’ll construct portable PLAL device controlling of the main factors of PLAL to synthesis a lot of compounds in nanoscale level . And we’ll focus to produce high yield of nanostructures by PLAL.
Conclusion
Fig.3: Diagram of mechanism of laser system
Fig.4: Pulsed laser Ablation in Liquid environmental (PLAL) system
Fig.5: Scanning Pulsed laser Ablation in Liquid environmental (PLAL) system
Adjustment of the focused pulsed laser
• The synthesis of CdS nanostructures by PLAL was carried via two ways; the first one is Top-Down technique appeared in publications in the last few decades while the other one is Bottom-Up technique appeared to be the first time in this study. • Nano CdS were synthesized by PLAL method that was tightly controlled during and after the ablation process. It was affected by number of factors playing a crucial role on controlling shape and size of the produced nanostructures.
References 5
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Fig.6: Diagram of Knife edge method
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Fig.7: Diagram of connected microphone to adjust the focusing
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