Direct laser fabrication of nanostructures on Si(001)

2015 ◽  
Vol 1748 ◽  
Author(s):  
Anahita Haghizadeh ◽  
Haeyeon Yang
Keyword(s):  
Laser Pulses ◽  
Surface Strain ◽  
Power Laser ◽  
Laser Fabrication ◽  
Force Microscopy ◽  
Atomic Force ◽  
Direct Laser ◽  
Direct Laser Fabrication ◽  
Transient Thermal ◽  
Base Width

ABSTRACTWe study how the period of transient thermal gradient impacts on morphologies of nanostructures on the Si(001) surface. Strain-free, self-assembled nanodots as well as periodic nanowires are fabricated directly on Si(001) surfaces by applying high power laser pulses on the surface interferentially. The morphologies of the nanostructures are studied by atomic force microscopy. Generally, the laser irradiated surfaces show nanowires but nanodots are also observed. The nanowire width increases with interference period. The narrowest nanowires observed have the width smaller than 50 nm, which is four times smaller than the interference period while the nanodots have a base width of 43 nm and height of 8 nm.

High density quantum dots by direct laser fabrication

MRS Advances ◽  
2016 ◽  
Vol 1 (28) ◽  
pp. 2025-2030 ◽  
Author(s):  
Anahita Haghizadeh ◽  
Haeyeon Yang
Keyword(s):  
Quantum Dots ◽  
Critical Density ◽  
Laser Pulses ◽  
High Density ◽  
Power Laser ◽  
Laser Fabrication ◽  
Force Microscopy ◽  
Atomic Force ◽  
Direct Laser ◽  
Direct Laser Fabrication

ABSTRACTWe report a study of direct laser fabrication that produces quantum dots with their density higher than the critical density without appearance of large clumps. Atomic force microscopy is used to image GaAs(001) surfaces that are irradiated by high power laser pulses interferentially. The analysis suggests that high density quantum dots be fabricated directly on semiconductor surfaces during epitaxial growth processes.

Direct laser patterning of GaAs(001) surfaces

2014 ◽  
Vol 1628 ◽  
Author(s):  
Haeyeon Yang
Keyword(s):  
Laser Intensity ◽  
Laser Pulses ◽  
Patterned Surfaces ◽  
Power Laser ◽  
Force Microscopy ◽  
Patterned Surface ◽  
Laser Patterning ◽  
Atomic Force ◽  
Plateau Area ◽  
Direct Laser

ABSTRACTAnalysis of surface images indicates that GaAs(001) surfaces can be patterned directly by applying interferential irradiation of high power laser pulses on the surface. Atomic force microscopy (AFM) was used to image the patterned surfaces. The patterned surface shows strips that have the same separation as the interference period used. The direct laser patterning leaves the surface with trenches. The depth of trenches increases with the laser intensity and can be varied from few nanometers to a few hundred nanometers. At low laser intensity, strip shaped mound appears at the both edges of a trench, leaving a plateau area between them. The width of mound increases with the laser intensity, making the plateau area smaller. With a higher laser intensity, the plateau area disappear as the mounds merge together, forming a single strip between the adjacent trenches. AFM images from the patterned surface indicate that direct laser patterning can be used to fabricate nanostructures with a period smaller than that of the interference period as well as the wavelength of the laser used.

scholarly journals Two-Photon Polymerization of Albumin Hydrogel Nanowires Strengthened with Graphene Oxide

Biomimetics ◽  
2021 ◽  
Vol 6 (4) ◽  
pp. 66
Author(s):  
Nikita Nekrasov ◽  
Natalya Yakunina ◽  
Vladimir Nevolin ◽  
Ivan Bobrinetskiy ◽  
Pavel Vasilevsky ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Femtosecond Laser ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Nanoelectromechanical Systems ◽  
Force Microscopy ◽  
Two Photon ◽  
Direct Laser ◽  
Two Photon Polymerization

Multifunctional biomaterials can pave a way to novel types of micro- and nanoelectromechanical systems providing benefits in mimicking of biological functions in implantable, wearable structures. The production of biocomposites that hold both superior electrical and mechanical properties is still a challenging task. In this study, we aim to fabricate 3D printed hydrogel from a biocomposite of bovine serum albumin with graphene oxide (BSA@GO) using femtosecond laser processing. We have developed the method for functional BSA@GO composite nanostructuring based on both two-photon polymerization of nanofilaments and direct laser writing. The atomic-force microscopy was used to probe local electrical and mechanical properties of hydrogel BSA@GO nanowires. The improved local mechanical properties demonstrate synergistic effect in interaction of femtosecond laser pulses and novel composite structure.

Direct Laser Fabrication of Compositionally Complex Materials

2020 ◽  
pp. 147-163
Author(s):  
Jithin Joseph
Keyword(s):  
Additive Manufacturing ◽  
Great Promise ◽  
Filler Materials ◽  
Chemical Homogeneity ◽  
Laser Fabrication ◽  
Direct Laser ◽  
Direct Laser Fabrication ◽  
Aerospace Medical ◽  
Complex Engineering ◽  
Cost Efficient

Additive manufacturing (AM) opens up the possibility of a direct build-up of components with sophisticated internal features or overhangs that are difficult to manufacture by a single conventional method. As a cost-efficient, tool-free, and digital approach to manufacturing components with complex geometries, AM of metals offers many critical benefits to various sectors such as aerospace, medical, automotive, and energy compared to conventional manufacturing processes. Direct laser fabrication (DLF) uses pre-alloyed powder mix or in-situ alloying of the elemental powders for metal additive manufacturing with excellent chemical homogeneity. It, therefore, shows great promise to enable the production of complex engineering components. This technique allows the highest build rates of the AM techniques with no restrictions on deposit size/shape and the fabrication of graded and hybrid materials by simultaneously feeding different filler materials. The advantages and disadvantages of DLF on the fabrication of compositionally complex metallic alloys are discussed in the chapter.

scholarly journals LIPSS Structures Induced on Graphene-Polystyrene Composite

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3460 ◽  
Author(s):  
Dominik Fajstavr ◽  
Klára Neznalová ◽  
Václav Švorčík ◽  
Petr Slepička
Keyword(s):  
Chemical Properties ◽  
Laser Pulses ◽  
Periodic Pattern ◽  
Krypton Fluoride ◽  
Periodic Surface ◽  
Laser Modification ◽  
Force Microscopy ◽  
Periodic Surface Structure ◽  
Atomic Force ◽  
Physico Chemical

A laser induced periodic surface structure (LIPSS) on graphene doped polystyrene was prepared by the means of a krypton fluoride (KrF) laser with the wavelength of 248 nm and precisely desired physico-chemical properties were obtained for the structure. Surface morphology after laser modification of polystyrene (PS) doped with graphene nanoplatelets (GNP) was studied. Laser fluence values of modifying laser light varied between 0–40 mJ·cm−2 and were used on polymeric PS substrates doped with 10, 20, 30, and 40 wt. % of GNP. GNP were incorporated into PS substrate with the solvent casting method and further laser modification was achieved with the same amount of laser pulses of 6000. Formed nanostructures with a periodic pattern were examined by atomic force microscopy (AFM). The morphology was also studied with scanning electron microscopy SEM. Laser irradiation resulted in changes of chemical composition on the PS surface, such as growth of oxygen concentration. This was confirmed with energy-dispersive X-ray spectroscopy (EDS).

Nanoindentation Assisted Self-Assembly of Quantum Dots

2006 ◽  
Author(s):  
Curtis Taylor ◽  
Eric Stach ◽  
Gregory Salamo ◽  
Ajay Malshe
Keyword(s):  
Quantum Dots ◽  
Self Assembly ◽  
Surface Strain ◽  
Ex Situ ◽  
Atomic Step ◽  
Uniform Size ◽  
Force Microscopy ◽  
Atomic Force ◽  
And Performance ◽  
Spatial Positioning

The ability to pattern quantum dots with high spatial positioning and uniform size is critical for the realization of future electronic devices with novel properties and performance that surpass present technology. This work discusses the exploration of an innovative nanopatterning technique to direct the self-assembly of nanostructures. The technique focuses on perturbing surface strain energy by nanoindentation in order to mechanically bias quantum dot nucleation. Growth of InAs quantum dots on nanoindent templates is performed using molecular beam epitaxy (MBE). The effect of indent spacing and size on the patterned growth is investigated. The structural analysis of the quantum dots including spatial ordering, size, and shape are characterized by ex-situ atomic force microscopy (AFM). Results reveal that the indent patterns clearly bias nucleation with dot structures selectively growing on top of each indent. It is speculated that the biased nucleation is due to a combination of favorable surface strain attributed to subsurface dislocation strain fields and/or multi-atomic step formation at the indent sites, which leads to increased adatom diffusion on the patterned area.

Direct Laser Fabrication of Defect Layers in Three-DimensionalChalcogenide Chiral Composites

2013 ◽  
Author(s):  
Benjamin P. Cumming ◽  
Mark. D. Turner ◽  
Sukanta Debbarma ◽  
Barry Luther-Davis ◽  
Gerd E. Schröder-Turk ◽  
...  
Keyword(s):  
Laser Fabrication ◽  
Direct Laser ◽  
Direct Laser Fabrication
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