Large area porous 1D photonic crystals comprising silicon hierarchical nanostructures grown by plasma-assisted, nanoparticle jet deposition

Abstract

In this contribution, we describe a room-temperature, template-free, single-step approach for the growth of functional crystalline silicon nanostructures with tailored porosity and photonic properties. The method employs a plasma-assisted nanoparticle synthesis reactor in combination with a supersonic jet deposition stage, in what we call nanoparticle jet deposition or plasma-assisted, supersonic aerosol jet deposition. The relationship between plasma parameters, nanoparticle impaction conditions and the resulting silicon material structural characteristics is investigated. This understanding is successfully employed for the production of porous 1D photonic crystals obtained by periodically modulating the density of the hierarchical silicon nanostructures and hence their local refractive index. The open porosity of this device is then exploited in a proof of concept optical chemical sensor.

Hierarchical TiN Nanostructured Thin Film Electrode for Highly Stable PEM Fuel Cells

“…The HTNTF is fabricated exploiting the room-temperature self-assembly of clusters from the gas phase produced in a supersonic plasma plume interacting with a background gas, in what we call a scattered ballistic deposition, SBD. The supersonic plasma plume can be generated by a laser ablating a solid target, which is the case of pulsed laser deposition operated in SBD mode or PL–SBD, − or by a nonthermal low-pressure plasma jet in a continuous flow arrangement, LPPJ–SBD. − In this communication we choose to use PL–SBD because of its intrinsic higher simplicity. Nevertheless, it is important to mention the recent demonstration of TiN nanoparticles production, in powder form, by a low-pressure continuous flow reactor. , In PL–SBD a crystalline TiN target is placed in a vacuum chamber in a nitrogen–5% hydrogen atmosphere, and a pulsed excimer laser is focused on it generating a supersonic plasma plume which expands toward the substrates placed head-on .…”

Stabilizing the Plasmonic Response of Titanium Nitride Nanocrystals with a Silicon Oxynitride Shell: Implications for Refractory Optical Materials

“…A pneumatic shutter is used to regulate the deposition time ensuring control of the thin-film thickness. More details about the presented thin-film synthesis approach can be found in previous publications. − The thin films are typically porous with density well below 50–60% of the material bulk density . The nanoparticles are impacted onto crystalline silicon wafers oxidized for 1 h in air at 1000 °C to produce an 80 nm layer of a Si/SiO 2 (silicon oxide) substrate.…”

“…30−33 The thin films are typically porous with density well below 50−60% of the material bulk density. 30 The nanoparticles are impacted onto crystalline silicon wafers oxidized for 1 h in air at 1000 °C to produce an 80 nm layer of a Si/SiO 2 (silicon oxide) substrate. The wafers are cut into 8 mm × 8 mm squares and used as substrates.…”

Mechanical behavior of SiNC layers on PDMS: effects of layer thickness, PDMS modulus, and SiNC surface functionality

“…[25][26][27] The stand-off distance between orice outlet and the top surface of PDMS substrate was kept constant at $4-5 mm to ensure consistency with our prior work. 17,25,26 We rastered the PDMS substrates beneath the orice to achieve uniform lm deposition.…”

“…17,23,24 The nanocrystals were deposited on the PDMS as thin-lm layers by inertial impaction onto a substrate placed beneath a slit-shaped orice. [25][26][27] The stand-off distance between orice outlet and the top surface of PDMS substrate was kept constant at $4-5 mm to ensure consistency with our prior work. 17,25,26 We rastered the PDMS substrates beneath the orice to achieve uniform lm deposition.…”