A5055614248- Photonic and Optical Devices
- Near-Field Optical Microscopy
- Optical Coatings and Gratings
- Plasmonic and Surface Plasmon Research
- 2D Materials and Applications
- Photonic Crystals and Applications
- Quantum Dots Synthesis And Properties
- Gold and Silver Nanoparticles Synthesis and Applications
- Semiconductor Lasers and Optical Devices
- Fluid Dynamics and Thin Films
- Thermal Radiation and Cooling Technologies
- Integrated Circuits and Semiconductor Failure Analysis
- Metamaterials and Metasurfaces Applications
- Orbital Angular Momentum in Optics
- Chalcogenide Semiconductor Thin Films
- Solar Thermal and Photovoltaic Systems
- Graphene research and applications
- Nanowire Synthesis and Applications
- Thermal properties of materials
- Advanced Thermodynamics and Statistical Mechanics
- Diamond and Carbon-based Materials Research
- Perovskite Materials and Applications
- Photovoltaic System Optimization Techniques
- GaN-based semiconductor devices and materials
- Metal and Thin Film Mechanics
Trinity College Dublin
2015-2024
Advanced Materials and BioEngineering Research
2015-2024
22q11 Ireland
2021
Institute of Photonic Sciences
2011-2018
National Institute of Standards and Technology
2013
Institut Fresnel
2013
Centre National de la Recherche Scientifique
2013
Aix-Marseille Université
2013
Institució Catalana de Recerca i Estudis Avançats
2013
University of Illinois Urbana-Champaign
2011
We study the ability of a plasmonic structure under illumination to release heat and induce fluid convection at nanoscale. first introduce unified formalism associated with this multidisciplinary problem combining optics, thermodynamics, hydrodynamics. On basis, numerical simulations were performed compute temperature field velocity evolutions surrounding for gold disk on glass while illuminated its plasmon resonance. show that amplitude has linear dependence quadratic size (for given...
Here we demonstrate inkjet printing of nanosheets both graphene and MoS2 prepared by liquid exfoliation. We describe a protocol for the preparation inks with well-defined size distribution concentration up to 6 mg ml−1. Graphene traces were printed at low temperature (<70 °C) no subsequent thermal or chemical treatment. Thin displayed percolation effects while thickness above 160 nm thickness-independent conductivity 3000 S m−1. also semiconducting using solvent-exfoliated, size-selected...
Liquid phase exfoliation is a powerful and scalable technique to produce defect-free mono- few-layer graphene. However, samples are typically polydisperse control over size thickness challenging. Notably, high throughput techniques measure lacking. In this work, we have measured the extinction, absorption, scattering Raman spectra for liquid exfoliated graphene nanosheets of various lateral sizes (90 ≤ 〈L〉 810 nm) thicknesses (2.7 〈N〉 10.4). We found all show well-defined dependences on...
Here, we demonstrate the production of large quantities gallium sulfide (GaS) nanosheets by liquid exfoliation layered GaS powder. The was achieved sonication powder in suitable solvents. variation dispersed concentration with solvent consistent classical solution thermodynamics and showed successful solvents to be those Hildebrand solubility parameters close 21.5 MPa1/2. In this way, could produced at concentrations up ∼0.2 mg/mL lateral sizes thicknesses 50–1000 nm 3–80 layers,...
Solution-exfoliated MoS2 nano-platelets were formed into thin films by deposition onto a water surface followed transfer to indium tin oxide coated glass. After drying, gold electrode was evaporated on top give sandwich structure with quasi-Ohmic contacts. Illumination of this device broadband light ∼1 kW m−2 intensity gave fourfold increase in conductivity. The photocurrent increased sub-linearly and exponentially time indicating the presence traps. photo-responsively at low ∼10−4 A per W...
High intensity sub-wavelength spots and low divergence nanojets are observed in a system of Si 3 N 4 microdisks illuminated from the side with laser light wavelengths 488 nm, 532 nm 633 nm.The disks height 400 diameters ranging 1µm to 10µm.Light scattered disk substrate is by imaging above.In free space focused inside sub wavelength spot observed, whereas water refractive index contrast such that photonic formed.The angular distribution compares well analytical solution for case an infinite...
Optically transparent photodetectors are crucial in next-generation optoelectronic applications including smart windows and image sensors. Designing with high transparency, photoresponsivity, robust mechanical flexibility remains a significant challenge, as is managing the inevitable trade-off between transparency strong photoresponse. Here we report scalable method to produce flexible crystalline Si nanostructured wire (NW) networks fabricated from silicon-on-insulator (SOI) seamless...
In this article, we present a comprehensive investigation of the photothermal properties plasmonic nanowire networks. We measure local steady-state temperature increase, heat source density, and absorption in Ag, Au, Ni metallic networks under optical illumination. This allows direct experimental confirmation increased generation at junction between two nanowires stacking-dependent polarized light. Due to thermal collective effects, distribution network is shown be completely delocalized on...
This article introduces an optical microscopy technique for the characterization of two-dimensional (2D) materials. The is based on use quadriwave lateral shearing interferometry (QLSI), a quantitative phase imaging that allows both intensity and incoming light beam. shows how QLSI can be used to (i) image 2D materials with high contrast transparent substrates, (ii) detect presence residues coming from fabrication process, (iii) map complex conductivity refractive index by processing images...
Thin-film thermoelectric coolers are emerging as a viable option for the on-chip temperature management of electronic and photonic integrated circuits. In this work, we demonstrate record heat flux handling capability electrodeposited Bi2Te3 films 720(±60) W cm–2 at room temperature, achieved by careful control contact interfaces to reduce resistance. The characteristic parameters single leg thin-film devices were measured in situ, giving Seebeck coefficient S = −121(±6) μV K–1, thermal...
In spite of the strong interest in brain‐like or neuromorphic computation, relatively few devices have emerged whose behavior is embedded hardware itself and not reliant on external programming synaptic weights. Here, a device described based TiO 2 nanowire that exhibits an associative memory response to time correlation between voltage optical stimuli. Memristive characteristics are also observed with current–voltage sweeps showing hysteresis loops continuum resistance levels. The responds...
PtS<sub>2</sub> and PtS thin films are synthesised by direct sulfurisation of Pt. X-ray photoelectron Raman spectroscopy used to unambiguously characterize both materials, providing a benchmark for future studies.
We report on position and density control of nitrogen-vacancy (NV) centres created in type Ib diamond using localised exposure from a helium ion microscope subsequent annealing. Spatial to &lt;380 nm has been achieved. show that the fluorescence lifetime decreases with increasing dose. Furthermore, we for doses &gt;1 × 1017 ion/cm2, significant damage lattice occurs resulting quenching amorphization. This places an upper limit NV can be this method.
Nonlinear optical scattering from single- and few-layer MoS2 contains important information about the orientation, inversion symmetry, degree of interlayer coupling between layers. We simultaneously map second harmonic generation (SHG) four wave mixing (FWM) signals in chemical vapor deposition (CVD) grown 2H-phase single to five tune excitation wavelengths compare cases where nonlinear are on off resonance with A-exciton band. The SHG signal shows expected 4-fold however, FWM depends...
The use of a metallic adhesion layer is known to increase the thermo-mechanical stability Au thin films against solid-state dewetting, but in turn results damping plasmonic response, reducing their utility applications such as heat-assisted magnetic recording (HAMR). In this work, 50 nm with Ti layers ranging thickness from 0 5 were fabricated, and thermal stability, electrical resistivity, response measured. Subnanometer are demonstrated significantly dewetting at elevated temperatures...
Abstract This report demonstrates highly efficient nonradiative energy transfer (NRET) from alloyed CdSeS/ZnS semiconductor nanocrystal quantum dots (QDs) to MoS 2 films of varying layer thicknesses, including pristine monolayers, mixed monolayer/bilayer, polycrystalline bilayers, and bulk‐like with NRET efficiencies over 90%. Large‐area are grown on Si/SiO substrates by chemical vapor deposition. Despite the ultrahigh there is no distinct increase in photoluminescence intensity. However,...
We report on the optical performance of metallic nanohelices as extension helical antenna concept into wavelength range. These nanoparticles exhibit a structure and material dependent response due to existence longitudinal localized-plasmon resonance which scales linearly with total length helix; thus, comprising number turns single-turn nanohelix. This is in contrast macroscopic helices, where scaling their operational mode only determined by single turn. show how plasmon damping radiated...
We report on a method to produce multiple-pitch, regularly shaped, aligned, and freestanding metallic nano-helices at room temperature. This overcomes the limitations of standard glancing angle deposition approach through heat-management technique devoid active substrate cooling is even applicable for metals with low melting point, that is, high surface adatom diffusion. The structural quality optical activity response these metal are comparable state art helices produced by employing...
Abstract Reproducible and enhanced optical detection of molecules in low concentrations demands simultaneously intense homogeneous electric fields acting as robust signal amplifiers. To generate such sophisticated near-fields, different plasmonic nanostructures were investigated recent years. These, however, exhibit either high enhancement factor ( EF ) or spatial homogeneity but not both. Small interparticle gaps sharp show enormous EFs no near-field homogeneity. Meanwhile, approaches using...
We investigate a tapered, hybrid plasmonic waveguide which has previously been proposed as an optically efficient near-field transducer (NFT), or component thereof, in several devices aim to exploit nanofocused light. numerically analyze how light is transported through the and ultimately focused via effective-mode coupling taper optimization. Crucial dimensional parameters this optimization process are identified that not only necessary achieve maximum optical throughput, but also optimum...
Two distinct athermal bias current procedures based on thermal tuning are demonstrated for a low-cost, monotlithic, three section slotted single mode laser, achieving mode-hop free wavelength stability of ± 0.04 nm / 5 GHz over temperature range 8-47 °C. This is the first time that performance has been three-section laser with simple fabrication, and well within 50 grid spacing specified DWDM systems. similar to experiments more complex DS-DBR lasers, indicating strong can be achieved using...