Fluorescent carbon nano dots from lignite: unveiling the impeccable evidence for quantum confinement

2016 ◽  
Vol 18 (17) ◽  
pp. 12065-12073 ◽  
Author(s):  
Senthil Kumar Thiyagarajan ◽  
Suresh Raghupathy ◽  
Dharmalingam Palanivel ◽  
Kaviyarasan Raji ◽  
Perumal Ramamurthy
Keyword(s):  
Laser Ablation ◽  
Size Effect ◽  
Band Gap ◽  
Quantum Confinement ◽  
Optical Band Gap ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Quantum Size Effect ◽  
Quantum Size ◽  
Fluorescent Carbon

Pulsed laser ablation of lignite in EDA solution exfoliates CDs (CD3) which exhibit the influence of quantum size effect in tuning the optical band gap of CDs.

Production of microstructures in wide-band-gap and organic materials using pulsed laser ablation at 157 nm wavelength

2010 ◽  
Vol 101 (3) ◽  
pp. 491-495 ◽  
Author(s):  
Falk Haehnel ◽  
Rene Bertram ◽  
Guenter Reisse ◽  
Rene Boettcher ◽  
Steffen Weissmantel
Keyword(s):  
Laser Ablation ◽  
Band Gap ◽  
Organic Materials ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Wide Band ◽  
Wide Band Gap

Quantum Confinement of GaAs Nanocrystals Deposited on PMMA Microspheres Using Pulsed Laser Ablation

2013 ◽  
Vol 660 ◽  
pp. 3-9
Author(s):  
Jeong Ho Ryu ◽  
Soon Yong Kweon ◽  
Jung Il Lee ◽  
Sung Lim Ryu
Keyword(s):  
Laser Ablation ◽  
Pulsed Laser Deposition ◽  
Quantum Confinement ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Average Diameter ◽  
Laser Deposition ◽  
Spherical Particles ◽  
Novel Approach

A modified pulsed laser deposition (PLD) was employed to deposit GaAs nanocrystals on the surface of PMMA microspheres. This novel approach is distinguished by the fact that laser ablated materials are deposited uniformly onto the surface of spherical particles that are held constantly in a particle fludization unit. The XRD, SEM, EDX, TEM, EDP and PL results confirmed that cubic structured GaAs nanocrystals were deposited uniformly on the surface of PMMA microspheres with an average diameter of about 15 nm.

Band gap modulation in CdSxSe1−xnanowires synthesized by a pulsed laser ablation with the Au catalyst

2006 ◽  
Vol 17 (15) ◽  
pp. 3775-3778 ◽  
Author(s):  
Young-Jin Choi ◽  
In-Sung Hwang ◽  
Jae-Hwan Park ◽  
Sahn Nahm ◽  
Jae-Gwan Park
Keyword(s):  
Laser Ablation ◽  
Band Gap ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Au Catalyst ◽  
Band Gap Modulation

Luminescence of Direct and Indirect Gap Quantum Semiconductor Crystallites

1992 ◽  
Vol 272 ◽  
Author(s):  
L. E. Brus
Keyword(s):  
Quantum Dots ◽  
Size Effect ◽  
Band Gap ◽  
Three Dimensional ◽  
Electronic States ◽  
Quantum Size Effect ◽  
Excited Electronic States ◽  
Quantum Size ◽  
Quantum Semiconductor ◽  
Bulk Band

Semiconductor crystallites (“quantum dots”) small with respect to the bulk exciton Bohr diameter show a three dimensional electronic quantum size effect. Their internal excited electronic states are discrete and shifted to higher energy than the bulk band gap[1,2].

Synthesis of water-soluble fluorescent carbon nanoparticles (CNPs) from nanosecond pulsed laser ablation in ethanol

2021 ◽  
Vol 135 ◽  
pp. 106717
Author(s):  
Gaurav Kumar Yogesh ◽  
E.P. Shuaib ◽  
A. Kalai Priya ◽  
P. Rohini ◽  
Sathyan Vivekanand Anandhan ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Carbon Nanoparticles ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Water Soluble ◽  
Nanosecond Pulsed Laser ◽  
Fluorescent Carbon Nanoparticles ◽  
Fluorescent Carbon

scholarly journals Laser Induced Anchoring of Nickel Oxide Nanoparticles on Polymeric Graphitic Carbon Nitride Sheets Using Pulsed Laser Ablation for Efficient Water Splitting under Visible Light

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1098 ◽  
Author(s):  
Umair Baig ◽  
Abuzar Khan ◽  
Mohammad A. Gondal ◽  
Mohamed A. Dastageer ◽  
Wail S. Falath
Keyword(s):  
Laser Ablation ◽  
Visible Light ◽  
Nickel Oxide ◽  
Band Gap ◽  
Water Splitting ◽  
Carbon Nitride ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Photocurrent Density ◽  
Photoelectrochemical Performance

A visible-light-active nickel oxide–graphitic carbon nitride (NiO@g-CN) hetero-structured nanocomposite was synthesized for the first time by pulsed laser ablation in liquid and used as a photoanode material in photoelectrochemical water-splitting reaction with a solar simulator. It was found that the photoelectrochemical performance of PLAL synthesized NiO@g-CN nanocomposite as photoanode, compared to g-CN as photoanode showed fourfold enhancements in photocurrent density under visible light. FT-IR, XRD, FE-SEM, and EDX consistently showed the proper anchoring of nano-sized NiO on g-CN. UV-DRS and the band gap estimation showed the narrowing down of the band gap energy and consequent enhancement in the visible-light absorption, whereas photoluminescence spectroscopy confirmed the reduction of the recombination of photo-excited electron hole pairs as a result of the anchoring of NiO on g-CN. The photoelectrochemical performance of g-CN and the NiO@g-CN nanocomposite photoanodes was compared by linear sweep voltammetry (LSV), Chronoamperometry (I-t), and Electrochemical Impedance Spectroscopy (EIS). All of these results of the characterization studies account for the observed fourfold enhancement of photocurrent density of NiO@g-CN nanocomposite as photoanode in the photoelectrochemical reaction.

Quantum confinement effect of nanocrystalline GaN films prepared by pulsed-laser ablation under various Ar pressures

2005 ◽  
Vol 471 (1-2) ◽  
pp. 273-276 ◽  
Author(s):  
Jong-Won Yoon ◽  
Takeshi Sasaki ◽  
Cheong Hyun Roh ◽  
Seung Hwan Shim ◽  
Kwang Bo Shim ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Quantum Confinement ◽  
Quantum Confinement Effect ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Confinement Effect

Phenomenological Modeling of Confined Phonon States in TMD Quantum Dots

MRS Advances ◽  
2018 ◽  
Vol 3 (6-7) ◽  
pp. 339-344 ◽  
Author(s):  
Lu Fang ◽  
Tamia Willliam ◽  
Kofi W. Adu ◽  
Mauricio Terrones
Keyword(s):  
Quantum Dots ◽  
Size Effect ◽  
Band Gap ◽  
Bulk Material ◽  
Single Layer ◽  
Interlayer Coupling ◽  
Quantum Size Effect ◽  
Quantum Size ◽  
Indirect Band Gap ◽  
Band Gap Tuning

ABSTRACTSeveral reports have shown band-gap tuning in TMDs, from indirect band gap in the bulk material to a direct gap in single layer due to the absence of interlayer coupling. This unique property stems from the modified electronic states. The phononic properties are extremely modified as well, due to layered effect and quantum size effect. There are several reports on layered effect; however, reports on the confined phonon states in these structures are limited. Thus, we present a preliminary studies of the confined phonon states in TMDs (WS2 and MoS2) quantum dots, and elucidate on the evolution of the phonon lineshape with diameter using a phenomenological model with an envelop function that truncates the phonon wave at the surface of the quantum dot. Furthermore, we delineate the layered effect from the quantum size effect in the phonon lineshape of WS2 and MoS2.

Laser-Assisted Synthesis of Amorphous/Pseudoamorphous GaN Thin Films and Nanostructures

2006 ◽  
Vol 317-318 ◽  
pp. 585-588
Author(s):  
Seung Hwan Shim ◽  
Naoto Koshizaki ◽  
Jong Won Yoon ◽  
Kwang Bo Shim
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Laser Ablation ◽  
Chemical Composition ◽  
Room Temperature ◽  
Optical Band Gap ◽  
Laser Energy ◽  
Stoichiometric Composition ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation

Amorphous/pseudoamorphous GaN was prepared by pulsed-laser ablation at room temperature without any heat treatment. The structure and chemical composition of the specimens were systematically investigated. Laser ablation at low Ar pressure (<50Pa) led to deposition of smooth Ga-rich films, which is independent with laser energy. Under same pressures, as laser energy increased, the film stoichiometry changed from Ga-rich to near stoichiometric composition. Varying background Ar pressure strongly affected the product structure showing little effect on the chemical composition. Under higher pressure than 100 Pa, fine nanoparticles with a size of 5 nm rather than films were deposited on substrate due to the increased collision by plume confining. The optical band-gap of the deposited a-GaN is 2.8 eV for thin films and 3.9 eV for nanoparticles.

Sign in / Sign up

Export Citation Format

Share Document