Formation and multi-imaging analysis of nascent surface structures generated by femtosecond laser irradiation in silicon

2017 ◽  
Author(s):  
Felice Gesuele ◽  
Jijil J. J. Navas ◽  
Pasqualino Maddalena ◽  
Salvatore Amoruso
Keyword(s):  
Femtosecond Laser ◽  
Laser Irradiation ◽  
Surface Structures ◽  
Femtosecond Laser Irradiation ◽  
Imaging Analysis ◽  
Nascent Surface

Ultrafast Laser Induced Subwavelength Periodic Surface Structures on Semiconductors/Metals and Application to SERS Studies

MRS Advances ◽  
2016 ◽  
Vol 1 (49) ◽  
pp. 3317-3327 ◽  
Author(s):  
V. Saikiran ◽  
Mudasir H Dar ◽  
R. Kuladeep ◽  
Narayana Rao Desai
Keyword(s):  
Femtosecond Laser ◽  
Laser Irradiation ◽  
Gold Film ◽  
Low Frequency ◽  
Surface Enhanced Raman Spectroscopy ◽  
Surface Structures ◽  
Femtosecond Laser Irradiation ◽  
Gold Films ◽  
Periodic Surface ◽  
Different Thickness

ABSTRACTIn this manuscript a simple approach is discussed to fabricate uniform periodic surface structures on semiconductor surfaces by femtosecond laser irradiation for surface-enhanced Raman spectroscopy (SERS) applications. Gold films having different thickness are first deposited on semiconductor silicon (Si) surfaces and then periodic surface structures are fabricated by femtosecond laser irradiation. The periodic structures are observed to be uniform over a large area with chain type structure formation of gold and Si. We have studied the formation of these surface structures on Si surface by having different thickness gold films deposited on Si substrates. This approach of the fabrication of surface structures with the assistance of gold film is found to help in local field enhancement and hence work as suitable substrate for the SERS experiments. The conditions for achieving high enhancement factor in SERS with different gold film thicknesses are explored in detail. We also present here the formation of low frequency ripples on Silicon (Si) and high frequency as well as low frequency ripples on titanium (Ti) surface in air and water environments by irradiation with fs laser pulses. Different morphologies were observed on Ti surface depending upon the laser irradiation parameters and the surrounding dielectric medium.

Reduced bacterial adhesion on zirconium-based bulk metallic glasses by femtosecond laser nanostructuring

2019 ◽  
Vol 234 (4) ◽  
pp. 387-397 ◽  
Author(s):  
Cezhi Du ◽  
Chengyong Wang ◽  
Tao Zhang ◽  
Xin Yi ◽  
Jianyi Liang ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Laser Irradiation ◽  
Metallic Glasses ◽  
Bacterial Adhesion ◽  
Bulk Metallic Glasses ◽  
Surface Structures ◽  
Femtosecond Laser Irradiation ◽  
Adhesion Properties ◽  
Nanostructured Surfaces

As high-performing materials, bulk metallic glasses have attracted widespread attention for biomedical applications. Herein, the bacterial adhesion properties of femtosecond laser-nanostructured surfaces of four types of zirconium-based bulk metallic glasses are assessed. Laser-induced periodical surface structures and nanoparticle structures were fabricated by femtosecond laser irradiation under different energy intensities (0.23 and 2.3 J/mm2). Surface topography, roughness, wettability, and surface energy were investigated after femtosecond laser irradiation and the surface bacterial adhesion properties were explored using Escherichia coli and Staphylococcus aureus as respective representatives of Gram-negative and Gram-positive bacteria. 4′,6-Diamidino-2-phenylindole fluorescence staining was used to characterize and assess the bacterial surface coverage rate. The in vitro cytotoxicity of polished and laser-nanostructured surfaces was investigated using MC3T3-E cells. The obtained results demonstrate that femtosecond laser surface nanostructuring retained the amorphous structure of zirconium-based bulk metallic glasses and led to an obvious decrease in bacterial adhesion compared with polished surfaces. The inhibition of bacterial adhesion on laser-induced periodical surface structures was greater than on nanostructured surfaces after 24 h of bacterial incubation. In addition, femtosecond laser nanostructuring did not have an apparent effect on the cytotoxicity of zirconium-based bulk metallic glasses.

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.

Formation of laser-induced periodic surface structures on niobium by femtosecond laser irradiation

2014 ◽  
Vol 115 (17) ◽  
pp. 173101 ◽  
Author(s):  
A. Pan ◽  
A. Dias ◽  
M. Gomez-Aranzadi ◽  
S. M. Olaizola ◽  
A. Rodriguez
Keyword(s):  
Femtosecond Laser ◽  
Laser Irradiation ◽  
Surface Structures ◽  
Femtosecond Laser Irradiation ◽  
Periodic Surface

Generation of nano-bumps on transparent quartz glass surface under femtosecond laser irradiation

2008 ◽  
Author(s):  
Wei Guo ◽  
Zeng Bo Wang ◽  
Lin Li ◽  
Zhu Liu ◽  
Boris Luk’yanchuk ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Laser Irradiation ◽  
Quartz Glass ◽  
Glass Surface ◽  
Femtosecond Laser Irradiation

scholarly journals Condensation of Si-rich region inside soda-lime glass by parallel femtosecond laser irradiation

2014 ◽  
Vol 22 (13) ◽  
pp. 16493 ◽  
Author(s):  
Masaaki Sakakura ◽  
Kouhei Yoshimura ◽  
Torataro Kurita ◽  
Masahiro Shimizu ◽  
Yasuhiko Shimotsuma ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Laser Irradiation ◽  
Soda Lime ◽  
Femtosecond Laser Irradiation ◽  
Soda Lime Glass ◽  
Rich Region

scholarly journals Three- and four-photon excited upconversion luminescence in terbium doped lutetium silicate powders by femtosecond laser irradiation

2013 ◽  
Vol 3 (11) ◽  
pp. 1803 ◽  
Author(s):  
Nikifor Rakov ◽  
Whualkuer Lozano B. ◽  
Edilson L. Falcão-filho ◽  
Renato B. Guimarães ◽  
Glauco S. Maciel ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Laser Irradiation ◽  
Upconversion Luminescence ◽  
Femtosecond Laser Irradiation
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