scholarly journals Processing of Single-Walled Carbon Nanotubes with Femtosecond Laser Pulses

2019 ◽  
Vol 9 (19) ◽  
pp. 4022 ◽  
Author(s):  
Zeyad Almutairi ◽  
Kaleem Ahmad ◽  
Mosaad Alanazi ◽  
Abdulaziz Alhazaa
Keyword(s):  
Carbon Nanotubes ◽  
Femtosecond Laser ◽  
Laser Irradiation ◽  
Cost Effective ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Femtosecond Laser Irradiation ◽  
Single Wall Carbon Nanotubes ◽  
Glass Substrates ◽  
Focus Plane

There are continued efforts to process and join single wall carbon nanotubes (SWCNTs) in order to exploit their exceptional functional properties for real-world applications. In this work, we report experimental observations of femtosecond laser irradiation on SWCNTs, in order to process and join them through an efficient and cost-effective technique. The nanotubes were deagglomerated in ethanol by an ultrasonicator and thin slurries of SWCNTs were spread evenly on glass substrates. A laser micromachining workstation for laboratory FemtoLAB (workshop of photonics) has been employed to irradiate the different SWCNTs film samples. The effect of laser parameters, such as pulse wavelength, laser power, etc., were systematically tuned to see the possibility of joining the SWCNTs ropes. Several experiments have been performed to optimize the parameters on different samples of SWCNTs. In general, the nanotubes were mostly damaged by the infrared (1st harmonics femtosecond laser) irradiation on the focal plane. However, the less damaging effect was observed for second harmonics (green wavelength) irradiation. The results suggest some joining of nanotubes along the sides of the focus plane, as well as on the center at the brink of nanotubes. The joining is considered to be established within the region of the high field intensity of the exposed femtosecond laser beam.

Resonant ablation of single-wall carbon nanotubes by femtosecond laser pulses

Laser Physics ◽  
2014 ◽  
Vol 25 (1) ◽  
pp. 015902 ◽  
Author(s):  
N R Arutyunyan ◽  
M S Komlenok ◽  
V V Kononenko ◽  
V P Pashinin ◽  
A S Pozharov ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Femtosecond Laser ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Single Wall Carbon Nanotubes ◽  
Single Wall Carbon

scholarly journals Controlled pDNA Release in Gemini Cationic Lipoplexes by Femtosecond Laser Irradiation of Gold Nanostars

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1498
Author(s):  
Natalia Sánchez-Arribas ◽  
Pablo Díaz-Núñez ◽  
José Osío Barcina ◽  
Emilio Aicart ◽  
Elena Junquera ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Laser Irradiation ◽  
Near Infrared ◽  
Irradiation Time ◽  
Nir Spectroscopy ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Cationic Lipids ◽  
Femtosecond Laser Irradiation ◽  
Gold Nanostars

The design of nanovectors able to overcome biological barriers is one of the main challenges in biomedicine. Gemini cationic lipids are considered potential candidates for gene therapy due to their high biocompatibility and capacity to condense nucleic acids safely in the form of lipoplexes. However, this approach presents difficulties regarding genetic unpacking and, therefore, control over this process becomes crucial to ensure successful transfection. In this work, gemini cationic lipoplexes were prepared in the presence of plasmonic gold nanostars (AuNSs) to afford a nanovector that efficiently releases plasmid DNA (pDNA) upon irradiation with near-infrared femtosecond laser pulses. A critical AuNSs concentration of 50 pM and optimized laser power density of 400 mW led to successful pDNA release, whose efficiency could be further improved by increasing the irradiation time. Agarose gel electrophoresis was used to confirm pDNA release. UV-Vis-NIR spectroscopy and transmission electron microscopy studies were performed to monitor changes in the morphology of the AuNSs and lipoplexes after irradiation. From a physicochemical point of view, this study demonstrates that the use of AuNSs combined with gemini cationic lipoplexes allows control over pDNA release under ultrafast laser irradiation.

Direct Welding between Copper and Glass Substrates with Femtosecond Laser Pulses

2008 ◽  
Vol 1 ◽  
pp. 082601 ◽  
Author(s):  
Yasuyuki Ozeki ◽  
Tomoyuki Inoue ◽  
Takayuki Tamaki ◽  
Hideaki Yamaguchi ◽  
Satoshi Onda ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Glass Substrates

The Componential and Morphological Characteristics of Cu3N Induced by Femtosecond Laser Pulses

2014 ◽  
Vol 609-610 ◽  
pp. 135-140 ◽  
Author(s):  
Ning Yi Yuan ◽  
Shu Yong Wang ◽  
Jian Ning Ding ◽  
Jian Hua Qiu ◽  
Xiu Qing Wang ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Laser Power ◽  
Morphological Characteristics ◽  
Laser Pulses ◽  
Xrd Analysis ◽  
Femtosecond Laser Pulses ◽  
Femtosecond Laser Irradiation ◽  
Microelectronic Devices ◽  
Treated Sample ◽  
Evolutional Process

We systematically study the componential and morphological characteristics of Cu3N films induced by femtosecond laser irradiation on glass substrate. The experimental results demonstrate that with increase of laser power, significant changes on surface morphology can be observed, and coarse ripples structures present dominantly on film surfaces after irradiated by femtosecond laser. By XRD analysis of the treated sample area, componential evolutional process from the Cu3N to Cu can be revealed at with increase of laser power, which provides an attracting application prospect in the field of utilizing microelectronic devices.

Effect of hydrogen concentration on structure and photoelectric properties of a-Si:H films modified by femtosecond laser pulses

2014 ◽  
Vol 92 (7/8) ◽  
pp. 883-887 ◽  
Author(s):  
Mark Khenkin ◽  
Andrey Emelyanov ◽  
Andrey Kazanskii ◽  
Pavel Forsh ◽  
Martynas Beresna ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Hydrogen Concentration ◽  
Crystallization Process ◽  
Volume Fraction ◽  
Laser Pulses ◽  
Nanocrystalline Silicon ◽  
Femtosecond Laser Pulses ◽  
Femtosecond Laser Irradiation ◽  
Laser Crystallization ◽  
Photoelectric Properties

The crystallization of hydrogenated amorphous silicon films with femtosecond laser pulses is one of the promising ways to produce nanocrystalline silicon for photovoltaics. The structure of laser treated films and their hydrogen content are the most important factors for determining the photoelectric properties of materials. In this work we investigated the effect of femtosecond laser irradiation of a-Si:H films with different fluences on crystalline volume fraction, hydrogen concentration, and photoelectric properties of this material. Our results point out that hydrogen out-diffusion accompanies the crystallization process. The increase of hydrogen concentration in the initial a-Si:H films structure affects the kinetics of the crystallization process, but does not lead to a substantial increase of hydrogen concentration remaining in the film after the treatment. The deficiency of hydrogen in the films’ structure results in degradation of their photoconductivity, thus other strategies of a-Si:H laser crystallization or postprocessing should be found to obtain device-quality films using ultrafast laser processing.

Structural Modification of Amorphous Fused Silica Under Femtosecond Laser Irradiation

2008 ◽  
Author(s):  
S. Vukelic ◽  
B. Gao ◽  
S. Ryu ◽  
Y. L. Yao
Keyword(s):  
Femtosecond Laser ◽  
Material Properties ◽  
Structural Changes ◽  
Three Dimensional ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Fused Silica ◽  
Femtosecond Laser Irradiation ◽  
Optical Data ◽  
Linear Absorption

Non-linear absorption of femtosecond laser pulses enables the induction of structural changes in the interior of bulk transparent materials without affecting their surface. This property can be exploited for the transmission welding of transparent dielectrics, three dimensional optical data storages and waveguides. In the present study, femtosecond laser pulses were tightly focused within the interior of bulk fused silica specimen. Localized plasma was formed, initiating rearrangement of the network structure. The change in material properties were studied through employment of spatially resolved Raman spectroscopy, atomic force microscopy and optical microscopy. The nature of the physical mechanisms responsible for the alteration of material properties as a function of process parameters is discussed.

scholarly journals Terahertz and Photoelectron Emission from Nanoporous Gold Films on Semiconductors

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 419
Author(s):  
Junyi Nan ◽  
Min Li ◽  
Ling Zhang ◽  
Shuai Yuan ◽  
Boqu He ◽  
...  
Keyword(s):  
Refractive Index ◽  
Femtosecond Laser ◽  
Incident Light ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Reflection Spectroscopy ◽  
Photoelectron Emission ◽  
Sio2 Substrate ◽  
Glass Substrates ◽  
Porous Gold

Efficient terahertz and photoelectron emission were observed from nano-porous gold (NPG) films deposited on an intrinsic gallium arsenide (GaAs) semiconductor substrate stimulated by femtosecond laser with pulse width of 60 fs. Time-domain THz emission and reflection spectroscopy confirmed that the free charges accelerated by irradiated femtosecond laser pulses transferred from the NPG films into the GaAs substrates. Accordingly, charges accumulation was reduced in the NPG films, resulting in a stronger emission of THz pulse than that from NPG films deposited on SiO2 substrate. Charges injected into the GaAs substrate enforced an observable decrease of the THz refractive index proportional to the intensity of incident light. In comparison, for NPG deposited on glass substrates, laser induced free charges were accumulated in the NPG films, and femtosecond laser pulses irradiating on the NPG films made no changes of the THz refractive index of the glass substrates.

scholarly journals Fabricating Femtosecond Laser-Induced Periodic Surface Structures with Electrophysical Anisotropy on Amorphous Silicon

Nanomaterials ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 42
Author(s):  
Dmitrii Shuleiko ◽  
Mikhail Martyshov ◽  
Dmitrii Amasev ◽  
Denis Presnov ◽  
Stanislav Zabotnov ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Laser Irradiation ◽  
Volume Fraction ◽  
Femtosecond Laser Pulses ◽  
Surface Structures ◽  
Femtosecond Laser Irradiation ◽  
Nanocrystalline Phase ◽  
Near Surface ◽  
Periodic Surface ◽  
Relief Formation

One-dimensional periodic surface structures were formed by femtosecond laser irradiation of amorphous hydrogenated silicon (a-Si:H) films. The a-Si:H laser processing conditions influence on the periodic relief formation as well as correlation of irradiated surfaces structural properties with their electrophysical properties were investigated. The surface structures with the period of 0.88 and 1.12 μm were fabricated at the laser wavelength of 1.25 μm and laser pulse number of 30 and 750, respectively. The orientation of the surface structure is defined by the laser polarization and depends on the concentration of nonequilibrium carriers excited by the femtosecond laser pulses in the near-surface region of the film, which affects a mode of the excited surface electromagnetic wave which is responsible for the periodic relief formation. Femtosecond laser irradiation increases the a-Si:H films conductivity by 3 to 4 orders of magnitude, up to 1.2 × 10−5 S∙cm, due to formation of Si nanocrystalline phase with the volume fraction from 17 to 28%. Dark conductivity and photoconductivity anisotropy, observed in the irradiated a-Si:H films is explained by a depolarizing effect inside periodic microscale relief, nonuniform crystalline Si phase distribution, as well as different carrier mobility and lifetime in plane of the studied samples along and perpendicular to the laser-induced periodic surface structures orientation, that was confirmed by the measured photoconductivity and absorption coefficient spectra.

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