7.2 Patterning and Assembly
219
Fig. 7.5 Sketch of a simple production method for homemade plasmonic nanoparticles. From a
laser source, 100-fs pulses are directed onto a TiN target in distilled water. By ablation, colloidal
TiN nanoparticles disperse in the solution and can be characterised for instance with a so-called
Nanosizer and Zetasizer [43]. Reproduced with permission. [43] Copyright 2017 Springer Nature
used for the ultrafast generation or the optically-gated detection of transient electric
fields. Plasmonic nanoparticles (PNPs) atop had been only introduced to serve as
scattering sites and light concentrators for better (optical) coupling into the underlying semiconductor in order to obtain a higher device performance. For such study,
TiN PNPs, which provide a comparably broad spectral response in the visible and
near-infrared region and a non-toxic composition, were prepared using two methods
and, thereby, different particle size distributions.
It is interesting to show that for lab-scale experiments, nanoparticles can be prepared by relatively simple means, e.g. direct ultrasonication and pulsed-laser ablation
in water using commercial nanopowders (TiN particles were sized narrowly around
20 nm in this example). The former technique resulted in an average PNP size of
about 200 nm in solution with a wide distribution of sizes, while the latter provided
particles in the range of 40 to 100 nm with average size about 60 nm. For laser ablation, a TiN target was produced by nanopowder compression and ablated by a 150-fs
pulsed Ti:sapphire laser at the bottom of a glass vessel filled with double-distilled
water (Fig. 7.5). After PNP production, a layer of self-prepared polydispersed TiN
PNPs was deposited on the surface of the employed bow-tie antennae using the
drop-casting method. Remarkably, this simple approach led to a noticeable—while
not ground-breaking—improvement of an existing THz antenna’s performance [43],
making use of plasmonics and nanoantenna concepts. A similar experiment with
THz antennae and nanoparticles was demonstrated shortly after with the similar aim
and conclusions [44].
219
Fig. 7.5 Sketch of a simple production method for homemade plasmonic nanoparticles. From a
laser source, 100-fs pulses are directed onto a TiN target in distilled water. By ablation, colloidal
TiN nanoparticles disperse in the solution and can be characterised for instance with a so-called
Nanosizer and Zetasizer [43]. Reproduced with permission. [43] Copyright 2017 Springer Nature
used for the ultrafast generation or the optically-gated detection of transient electric
fields. Plasmonic nanoparticles (PNPs) atop had been only introduced to serve as
scattering sites and light concentrators for better (optical) coupling into the underlying semiconductor in order to obtain a higher device performance. For such study,
TiN PNPs, which provide a comparably broad spectral response in the visible and
near-infrared region and a non-toxic composition, were prepared using two methods
and, thereby, different particle size distributions.
It is interesting to show that for lab-scale experiments, nanoparticles can be prepared by relatively simple means, e.g. direct ultrasonication and pulsed-laser ablation
in water using commercial nanopowders (TiN particles were sized narrowly around
20 nm in this example). The former technique resulted in an average PNP size of
about 200 nm in solution with a wide distribution of sizes, while the latter provided
particles in the range of 40 to 100 nm with average size about 60 nm. For laser ablation, a TiN target was produced by nanopowder compression and ablated by a 150-fs
pulsed Ti:sapphire laser at the bottom of a glass vessel filled with double-distilled
water (Fig. 7.5). After PNP production, a layer of self-prepared polydispersed TiN
PNPs was deposited on the surface of the employed bow-tie antennae using the
drop-casting method. Remarkably, this simple approach led to a noticeable—while
not ground-breaking—improvement of an existing THz antenna’s performance [43],
making use of plasmonics and nanoantenna concepts. A similar experiment with
THz antennae and nanoparticles was demonstrated shortly after with the similar aim
and conclusions [44].