ORCID Profile
0000-0002-8365-7504
Current Organisation
RMIT University
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Functional Materials | Nanotechnology | Materials Engineering | Nanofabrication, Growth and Self Assembly | Condensed Matter Physics | Microelectronics and Integrated Circuits | Nanophotonics | Nanoscale Characterisation | Communications Technologies | Condensed Matter Imaging | Microwave and Millimetrewave Theory and Technology | Condensed Matter Characterisation Technique Development | Signal Processing | Photonics and Electro-Optical Engineering (excl. Communications) | Analytical Chemistry | Biomedical Instrumentation | Medical Devices | Interdisciplinary Engineering not elsewhere classified | Sensor Technology (Chemical aspects) | Biomedical Engineering | Analytical Spectrometry | Electrical and Electronic Engineering | Medical Biotechnology not elsewhere classified | Nanotechnology not elsewhere classified | Biological Physics | Nanomaterials | Engineering Instrumentation | Antennas and Propagation | Photonics, Optoelectronics and Optical Communications | Nanobiotechnology | Nanoelectronics
ANZSRC Socio-Economic Objective (SEO)
Expanding Knowledge in Engineering | Expanding Knowledge in the Physical Sciences | Integrated Circuits and Devices | Expanding Knowledge in Technology | Expanding Knowledge in the Chemical Sciences | Scientific Instruments | Emerging Defence Technologies | Medical Instruments | Manufacturing not elsewhere classified | Ceramics, glass and industrial mineral products not elsewhere classified | Diagnostic Methods | Health Status (e.g. Indicators of Well-Being) | Diagnostics | Treatments (e.g. chemicals, antibiotics) |
Related Links
Publications
Nano-scale dielectric resonator antennas as building blocks for efficient manipulation of light
Publisher: IEEE
Date: 07-2015
Dual harmonic Kelvin probe force microscopy for surface potential measurements of ferroelectrics
Publisher: IEEE
Date: 07-2012
Flexible bi-layer terahertz chiral metamaterials
Publisher: IOP Publishing
Date: 20-07-2015
Donor-Induced Performance Tuning of Amorphous SrTiO 3 Memristive Nanodevices: Multistate Resistive Switching and Mechanical Tunability
Publisher: Wiley
Date: 14-04-2015
Composition analysis of nickel silicide formed from evaporated and sputtered nickel for microsystem devices
Publisher: Institution of Engineering and Technology (IET)
Date: 2007
DOI: 10.1049/EL:20070203
Enhanced charge carrier mobility in two-dimensional high dielectric molybdenum oxide
Publisher: Wiley
Date: 23-10-2013
Abstract: We demonstrate that the energy bandgap of layered, high-dielectric α-MoO(3) can be reduced to values viable for the fabrication of 2D electronic devices. This is achieved through embedding Coulomb charges within the high dielectric media, advantageously limiting charge scattering. As a result, devices with α-MoO(3) of ∼11 nm thickness and carrier mobilities larger than 1100 cm(2) V(-1) s(-1) are obtained.
Terahertz localized surface plasmon resonances in coaxial microcavities
Publisher: Wiley
Date: 21-05-2013
Dry electrode geometry optimization for wearable ECG devices
Publisher: AIP Publishing
Date: 07-2023
DOI: 10.1063/5.0152554
Engineering electrodeposited ZnO films and their memristive switching performance
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3CP44451A
Abstract: We report the influence of zinc oxide (ZnO) seed layers on the performance of ZnO-based memristive devices fabricated using an electrodeposition approach. The memristive element is based on a sandwich structure using Ag and Pt electrodes. The ZnO seed layer is employed to tune the morphology of the electrodeposited ZnO films in order to increase the grain boundary density as well as construct highly ordered arrangements of grain boundaries. Additionally, the seed layer also assists in optimizing the concentration of oxygen vacancies in the films. The fabricated devices exhibit memristive switching behaviour with symmetrical and asymmetrical hysteresis loops in the absence and presence of ZnO seed layers, respectively. A modest concentration of oxygen vacancy in electrodeposited ZnO films as well as an increase in the ordered arrangement of grain boundaries leads to higher switching ratios in Ag/ZnO/Pt devices.
Patterning of PLZT and PSZT thin films by excimer laser
Publisher: Springer Science and Business Media LLC
Date: 19-04-2008
Silicon-Nanotube-Mediated Intracellular Delivery Enables Ex Vivo Gene Editing
Publisher: Wiley
Date: 06-05-2020
Mechanically Tunable Terahertz Circular Polarizer with Versatile Functions
Publisher: Wiley
Date: 03-02-2023
Abstract: Circular polarizers that selectively transmit only one handedness of circular polarization are useful for imaging and wireless communications. Conventional circular polarizers involve 3D chiral structures, which impose fabrication challenges, while typically introducing chirality within a limited bandwidth. To overcome the limitations associated with conventional non‐planar designs, a three‐layer metasurface‐based planar circular polarizer exhibiting strong and broadband chirality is presented here. Its superiority over existing multilayer designs is derived from a systematic design procedure. Measurement results reveal that the proposed structure maintains a 15‐dB extinction ratio from 251 to 293 GHz for the preferred handedness of circular polarization, leading to a fractional bandwidth of 15.4% with a transmission efficiency above 92.7%. Furthermore, the proposed structure is mechanically tunable to alter its functionality or operation bandwidth. Specifically, through simply rotating the top or bottom metallic layer by 90°, the structure can function as a transmissive quasi‐half‐wave plate that reverses the sense of circular polarization. Moreover, the presented structure can operate at nearby frequency ranges for the aforementioned functionalities by mechanically adjusting the air gap spacings between the metallic layers. Further calculations based on the measured results of each layer suggest that the proposed structure is robust to deviations in the air gap spacings.
ZnO based thermopower wave sources
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2CC33146B
Abstract: Exothermic chemical reactions of nitrocellulose are coupled onto thermoelectric zinc oxide (ZnO) layers to generate self-propagating thermopower waves resulting in highly oscillatory voltage output of the order of 500 mV. The peak specific power obtained from ZnO based sources is approximately 0.5 kW kg(-1).
Acoustic-Excitonic Coupling for Dynamic Photoluminescence Manipulation of Quasi - 2D MoS 2 Nanoflakes
Publisher: Wiley
Date: 12-03-2015
Synthesis of Self-Assembled Island-Structured Complex Oxide Dielectric Films
Publisher: American Chemical Society (ACS)
Date: 09-2009
DOI: 10.1021/JP904832Z
In-plane anisotropic and ultra-low-loss polaritons in a natural van der Waals crystal
Publisher: Springer Science and Business Media LLC
Date: 10-2018
DOI: 10.1038/S41586-018-0618-9
Abstract: Polaritons-hybrid light-matter excitations-enable nanoscale control of light. Particularly large polariton field confinement and long lifetimes can be found in graphene and materials consisting of two-dimensional layers bound by weak van der Waals forces
Dielectrics for Terahertz Metasurfaces: Material Selection and Fabrication Techniques
Publisher: Wiley
Date: 25-09-2020
Lattice guiding for sputter deposition of single domain (Sr0.6Ba0.4)Nb2O6ferroelectric thin films
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C1CE06112G
Oxygen-deficient strontium titanate based stretchable resistive memories
Publisher: Elsevier BV
Date: 12-2018
Layered SAW gas sensor based on CSA synthesized polyaniline nanofiber on AlN on 64° YX LiNbO3 for H2 sensing
Publisher: Elsevier BV
Date: 04-2009
Polarization-dependent thin-film wire-grid reflectarray for terahertz waves
Publisher: AIP Publishing
Date: 20-07-2015
DOI: 10.1063/1.4927386
Abstract: A thin-film polarization-dependent reflectarray based on patterned metallic wire grids is realized at 1 THz. Unlike conventional reflectarrays with resonant elements and a solid metal ground, parallel narrow metal strips with uniform spacing are employed in this design to construct both the radiation elements and the ground plane. For each radiation element, a certain number of thin strips with an identical length are grouped to effectively form a patch resonator with equivalent performance. The ground plane is made of continuous metallic strips, similar to conventional wire-grid polarizers. The structure can deflect incident waves with the polarization parallel to the strips into a designed direction and transmit the orthogonal polarization component. Measured radiation patterns show reasonable deflection efficiency and high polarization discrimination. Utilizing this flexible device approach, similar reflectarray designs can be realized for conformal mounting onto surfaces of cylindrical or spherical devices for terahertz imaging and communications.
Nanoscale Characterization of Energy Generation from Piezoelectric Thin Films
Publisher: Wiley
Date: 04-04-2011
Black phosphorus: Ambient degradation and strategies for protection
Publisher: IOP Publishing
Date: 10-04-2018
Selected Peer-Reviewed Articles from 13th International Meeting on Chemical Sensors (IMCS-13)
Publisher: American Scientific Publishers
Date: 04-2011
DOI: 10.1166/SL.2011.1567
Metal-Loaded Dielectric Resonator Metasurfaces for Radiative Cooling
Publisher: Wiley
Date: 11-08-2017
Broadband terahertz transmissive quarter-wave metasurface
Publisher: AIP Publishing
Date: 09-2020
DOI: 10.1063/5.0017830
Abstract: Polarization conversion devices are key components in spectroscopy and wireless communications systems. Conventional terahertz waveplates made of natural birefringent materials typically suffer from low efficiency, narrow bandwidth, and substantial thickness. To overcome the limitations associated with conventional waveplates, a terahertz quarter-wave metasurface with enhanced efficiency and wide bandwidth is proposed. The transmissive quarter-wave metasurface is rigorously designed based on an extended semi-analytical approach employing network analysis and genetic algorithm. Simulation results suggest that the design can achieve linear-to-circular polarization conversion with a 3-dB axial ratio relative bandwidth of 53.3%, spanning 205 GHz–354 GHz. The measurement results confirm that the proposed design enables a 3-dB axial ratio from 205 GHz to at least 340 GHz with a total efficiency beyond 70.2%, where the upper frequency bound is limited by the available experimental facility. This quarter-wave metasurface can cover an entire terahertz electronics band and can be scaled to cover other nearby bands under the same convention, which are technologically significant for future portable systems.
Piezoelectric thin film deposition: Self-assembled island structures and low temperature processing
Publisher: IEEE
Date: 12-2010
Field effect biosensing platform based on 2D α-MoO3
Publisher: American Chemical Society (ACS)
Date: 07-11-2013
DOI: 10.1021/NN403241F
Abstract: Electrical-based biosensing platforms offer ease of fabrication and simple sensing solutions. Recently, two-dimensional (2D) semiconductors have been proven to be excellent for the fabrication of field effect transistors (FETs) due to their large transconductance, which can be efficiently used for developing sensitive bioplatforms. We present a 2D molybdenum trioxide (MoO3) FET based biosensing platform, using bovine serum albumin as a model protein. The conduction channel is a nanostructured film made of 2D α-MoO3 nanoflakes, with the majority of nanoflake thicknesses being equal to or less than 2.8 nm. The response time is impressively low (less than 10 s), which is due to the high permittivity of the 2D α-MoO3 nanoflakes. The system offers a competitive solution for future biosensing applications.
Influence of electric field on SERS: Frequency effects, intensity changes, and susceptible bonds
Publisher: American Chemical Society (ACS)
Date: 12-2012
DOI: 10.1021/JA208893Q
Abstract: The fundamental mechanism proposed to explain surface-enhanced Raman scattering (SERS) relies on electromagnetic field enhancement at optical frequencies. In this work, we demonstrate the use of microfabricated, silver nanotextured electrode pairs to study, in situ, the influence of low frequency (5 mHz to 1 kHz) oscillating electric fields on the SERS spectra of thiophenol. This applied electric field is shown to affect SERS peak intensities and influence specific vibrational modes of the analyte. The applied electric field perturbs the polar analyte, thereby altering the scattering cross section. Peaks related to the sulfurous bond which binds the molecule to the silver nanotexture exhibit strong and distinguishable responses to the applied field, due to varying bending and stretching mechanics. Density functional theory simulations are used to qualitatively verify the experimental observations. Our experimental and simulation results demonstrate that the SERS spectral changes relate to electric field induced molecular reorientation, with dependence on applied field strength and frequency. This demonstration creates new opportunities for external dynamic tuning and multivariate control of SERS measurements.
Planar terahertz metamaterials for strain sensing
Publisher: IEEE
Date: 09-2012
Emerging applications of metal-oxide thin films for flexible and stretchable electronic devices
Publisher: AIP Publishing
Date: 09-2023
DOI: 10.1063/5.0151297
Strain response of stretchable micro-electrodes: Controlling sensitivity with serpentine designs and encapsulation
Publisher: AIP Publishing
Date: 13-01-2014
DOI: 10.1063/1.4862264
Terahertz disk resonator on a substrateless dielectric waveguide platform
Publisher: Optica Publishing Group
Date: 31-08-2023
DOI: 10.1364/OL.499957
Abstract: Resonant cavities are fundamental to and versatile for terahertz integrated systems. So far, integrated resonant cavities have been implemented in relatively lossy terahertz platforms. In this Letter, we propose a series of integrated disk resonators built into a low-loss substrateless silicon waveguide platform, where the resonances and associated quality factor ( Q -factor) can be controlled via an effective medium. The measurement results demonstrate that the Q -factor can reach up to 9146 at 274.4 GHz due to the low dissipation of the platform. Additionally, these resonators show strong tunability of the resonance under moderate optical power. These terahertz integrated disk resonators can be employed in sensing and communications.
Near-field imaging of magnetic resonance in terahertz dielectric resonator antennas
Publisher: IEEE
Date: 09-2016
Solution-Processed VO2 Nanoparticle/Polymer Composite Films for Thermochromic Applications
Publisher: American Chemical Society (ACS)
Date: 20-07-2022
Terahertz bandpass frequency selective surface with improved out-of-band response
Publisher: IEEE
Date: 08-2015
Measurement of high piezoelectric response of strontium-doped lead zirconate titanate thin films using a nanoindenter
Publisher: AIP Publishing
Date: 15-05-2007
DOI: 10.1063/1.2735407
Abstract: Strontium-doped lead zirconate titanate (PSZT) is reported to have a high piezoelectric coefficient (d33) in the range of 200−600 pm∕V, when in the form of ceramic disks or pellets. This article reports piezoelectric response results for PSZT thin films deposited by rf magnetron sputtering on gold-coated silicon substrates. The compositions of the deposited thin films have been found to be uniform with depth, using secondary ion mass spectroscopy. The surfaces of the deposited thin films have been studied using an atomic force microscope and observed to be regular and nanostructured in nature. The piezoelectric response of the thin films, using the inverse piezoelectric effect, has been measured using a nanoindenter. Values of thin film d33 up to 608 pm∕V were obtained, which is much higher than previously reported values of d33 for any thin film. The high values can be attributed to optimized deposition conditions and the low stress measured for the thin film arrangement on the substrate. The technique has been verified by obtaining a null response for silicon dioxide and by measuring d33 values of similar magnitude for PSZT thin films using an atomic force microscope in the same testing arrangement. The piezoelectric response has been mapped to study variations across the thin film and with distance from the top electrode.
Ultrahigh‐Q Resonance in Bound States in the Continuum–Enabled Plasmonic Terahertz Metasurface
Publisher: Wiley
Date: 28-06-2023
Abstract: The study of optical resonators is of significant importance in terms of their ability to confine light in optical devices. A major drawback of optical resonators is the phenomenon of light emission due to their limited capacity for light confinement. Bound states in the continuum are gaining significant attention in the realization of optical devices due to their unique ability for reducing light scattering via interference mechanisms. This process can potentially suppress scattering, leading to improved optical performance. Using this concept, a metasurface having two elliptical silicon (Si) resonators nonidentically angled to create an out‐of‐plane asymmetry is studied. Various parameters are optimized by employing a genetic algorithm (GA) to subsequently achieve a high‐ Q factor at terahertz frequencies. Herein, the device is fabricated using a novel method, and a thick high‐index resonator is achieved. Terahertz measurements are carried out to validate the results. It is indicated in the experimental results that plasmons appear at the top surface of the metasurface and create strong sharp resonances that are sensitive to the external environment. Owing to strong field confinement ability, and high‐ Q factor, the metasurface is sensitive to its surrounding environment and can be essentially employed in terahertz sensing applications.
Large-area synthesis of 2D MoO 3− x for enhanced optoelectronic applications
Publisher: IOP Publishing
Date: 17-05-2019
Accurate Estimation of Low $( ≪ \hbox{10}^{-8}\ \Omega \cdot \hbox{cm}^{2})$ Values of Specific Contact Resistivity
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 03-2008
Broadband light active MTCNQ-based metal–organic semiconducting hybrids for enhanced redox catalysis
Publisher: Elsevier BV
Date: 12-2018
Two-dimensional MoO3 via a top-down chemical thinning route
Publisher: IOP Publishing
Date: 06-07-2017
Electron Emission Devices for Energy‐Efficient Systems
Publisher: Wiley
Date: 08-2019
Broadband Terahertz Circular-Polarization Beam Splitter
Publisher: Wiley
Date: 22-12-2018
Transparent functional oxide stretchable electronics: micro-tectonics enabled high strain electrodes
Publisher: Springer Science and Business Media LLC
Date: 09-2013
DOI: 10.1038/AM.2013.41
A Physical Unclonable Function with Redox-Based Nanoionic Resistive Memory
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 02-2018
Broadband terahertz reflective linear polarization convertor
Publisher: IEEE
Date: 09-2014
Metal–Air Transistors: Semiconductor-Free Field-Emission Air-Channel Nanoelectronics
Publisher: American Chemical Society (ACS)
Date: 16-11-2018
DOI: 10.1021/ACS.NANOLETT.8B02849
Abstract: Scattering-free transport in vacuum tubes has always been superior to solid-state transistors. It is the advanced fabrication with mass production capability at low cost which drove solid-state nanoelectronics. Here, we combine the best of vacuum tubes with advanced nanofabrication technology. We present nanoscale, metal-based, field emission air channel transistors. Comparative analysis of tungsten-, gold-, and platinum-based devices is presented. Devices are fabricated with electron beam lithography, achieving channel lengths less than 35 nm. With this small channel length, vacuum-like carrier transport is possible in air under room temperature and pressure. Source and drain electrodes have planar, symmetric, and sharp geometry. Because of this, devices operate in bidirection with voltages <2 V and current values in few tens of nano eres range. The experimental data shows that influential operation mechanism is Fowler-Nordheim tunnelling in tungsten and gold devices, while Schottky emission in platinum device. The presented work enables a technology where metal-based switchable nanoelectronics can be created on any dielectric surface with low energy requirements.
Electric field induced surface-enhanced Raman spectroscopy for multianalyte detection
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C4CP04912H
Abstract: This work demonstrates the ability to detect and isolate an analyte from a multianalyte mixture by SERS sensing.
Flexible metasurfaces and metamaterials: A review of materials and fabrication processes at micro- and nano-scales
Publisher: AIP Publishing
Date: 03-2015
DOI: 10.1063/1.4913751
Molybdenum Oxides – From Fundamentals to Functionality
Publisher: Wiley
Date: 16-08-2017
Abstract: The properties and applications of molybdenum oxides are reviewed in depth. Molybdenum is found in various oxide stoichiometries, which have been employed for different high-value research and commercial applications. The great chemical and physical characteristics of molybdenum oxides make them versatile and highly tunable for incorporation in optical, electronic, catalytic, bio, and energy systems. Variations in the oxidation states allow manipulation of the crystal structure, morphology, oxygen vacancies, and dopants, to control and engineer electronic states. Despite this overwhelming functionality and potential, a definitive resource on molybdenum oxide is still unavailable. The aim here is to provide such a resource, while presenting an insightful outlook into future prospective applications for molybdenum oxides.
2D/3D Hybrid of MoS2/GaN for a High-Performance Broadband Photodetector
Publisher: American Chemical Society (ACS)
Date: 02-05-2021
Effect of multi-layered bottom electrodes on the orientation of strontium-doped lead zirconate titanate thin films
Publisher: Elsevier BV
Date: 09-2008
Large area metal-silicone flexible electronic structures
Publisher: IEEE
Date: 12-2010
Analytical and Finite-Element Modeling of a Cross Kelvin Resistor Test Structure for Low Specific Contact Resistivity
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 10-2009
CNT/PDMS composite membranes for H2 and CH4 gas separation
Publisher: Elsevier BV
Date: 08-2013
Nanoindentation response of piezoelectric nano-islands
Publisher: AIP Publishing
Date: 22-09-2014
DOI: 10.1063/1.4896128
Abstract: Through three-dimensional finite element modeling, it is demonstrated that the nanoindentation response of piezoelectric nano-islands is strongly dependent on the shape of the nano-island and the depth of indentation. For indentations that are relatively deep (i.e., greater than 5% of the height of the islands), the substrate's elastic and plastic properties have a strong influence on the indentation response of piezoelectric nano-islands with substrate plasticity resulting in a significant reduction in the mechanical and electrical indentation stiffness. The predictions of the finite element models compare well with experiments on nano-islands of strontium-doped lead zirconate titanate.
Enhanced Charge Carrier Mobility in Two‐Dimensional High Dielectric Molybdenum Oxide (Adv. Mater. 1/2013)
Publisher: Wiley
Date: 02-01-2013
Silver nanoparticle/PDMS nanocomposite catalytic membranes for H2S gas removal
Publisher: Elsevier BV
Date: 11-2014
Nano-Intrinsic True Random Number Generation: A Device to Data Study
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-2019
In situ micro-Raman analysis and X-ray diffraction of nickel silicide thin films on silicon
Publisher: Elsevier BV
Date: 2009
DOI: 10.1016/J.MICRON.2008.03.007
Abstract: This article reports on the in situ analysis of nickel silicide (NiSi) thin films formed by thermal processing of nickel thin films deposited on silicon substrates. The in situ techniques employed for this study include micro-Raman spectroscopy (microRS) and X-ray diffraction (XRD) in both cases the variations for temperatures up to 350 degrees C has been studied. Nickel silicide thin films formed by vacuum annealing of nickel on silicon were used as a reference for these measurements. In situ analysis was carried out on nickel thin films on silicon, while the s les were heated from room temperature to 350 degrees C. Data was gathered at regular temperature intervals and other specific points of interest (such as 250 degrees C, where the reaction between nickel and silicon to form Ni(2)Si is expected). The transformations from the metallic state, through the intermediate reaction states, until the desired metal-silicon reaction product is attained, are discussed. The evolution of nickel silicide from the nickel film can be observed from both the microRS and XRD in situ studies. Variations in the evolution of silicide from metal for different silicon substrates are discussed, and these include (100) n-type, (100) p-type, and (110) p-type silicon substrates.
Stretchable and Tunable Microtectonic ZnO-Based Sensors and Photonics
Publisher: Wiley
Date: 05-06-2015
Abstract: The concept of realizing electronic applications on elastically stretchable "skins" that conform to irregularly shaped surfaces is revolutionizing fundamental research into mechanics and materials that can enable high performance stretchable devices. The ability to operate electronic devices under various mechanically stressed states can provide a set of unique functionalities that are beyond the capabilities of conventional rigid electronics. Here, a distinctive microtectonic effect enabled oxygen-deficient, nanopatterned zinc oxide (ZnO) thin films on an elastomeric substrate are introduced to realize large area, stretchable, transparent, and ultraportable sensors. The unique surface structures are exploited to create stretchable gas and ultraviolet light sensors, where the functional oxide itself is stretchable, both of which outperform their rigid counterparts under room temperature conditions. Nanoscale ZnO features are embedded in an elastomeric matrix function as tunable diffraction gratings, capable of sensing displacements with nanometre accuracy. These devices and the microtectonic oxide thin film approach show promise in enabling functional, transparent, and wearable electronics.
Graphene Analogues: Elemental Analogues of Graphene: Silicene, Germanene, Stanene, and Phosphorene (Small 6/2015)
Publisher: Wiley
Date: 02-2015
Erratum: Elevated temperature anodized Nb 2 O 5 -A photoanode material with exceptionally large photoconversion efficiencies (ACS Nano (2012) 6 (4045-4053) DOI: 10.1021/nn300408p)
Publisher: American Chemical Society (ACS)
Date: 31-05-2012
DOI: 10.1021/NN302256G
Sb2Te3 and Bi2Te3 based thermopower wave sources
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C1EE01370J
Wearable Label‐Free Optical Biodetectors: Progress and Perspectives
Publisher: Wiley
Date: 18-12-2020
Microengineered structures for rapid automatic loading of optical fibre segments
Publisher: IOP Publishing
Date: 04-08-2011
Nanoscale electro-mechanical dynamics of nano-crystalline platinum thin films: An in situ electrical nanoindentation study
Publisher: AIP Publishing
Date: 23-10-2014
DOI: 10.1063/1.4899194
Abstract: Here, we present a detailed methodology for the study of nano-electromechanical properties of thin films through in situ electrical nanoindentation. The nanomechanical properties of nano-crystalline platinum thin films have been accurately evaluated via nullifying multiple phenomena and artefacts that can introduce errors in interpreting nanoindentation experimental data. To gain quantified insights from in situ electrical measurements, an empirical equation is introduced to model the resistance imposed by the conductive probe at the nanoscale contact as a function indentation depth and load. Using the empirical model, nanoscale electrical properties of nano-crystalline platinum films are quantitatively evaluated. It is observed that the resistivity of the platinum increases subject to high contact pressure, which is also associated with substantial structural deformations around the nano-contact area.
Transition metal oxides - Thermoelectric properties
Publisher: Elsevier BV
Date: 10-2013
Solution-processable do-it-yourself switching devices (DIY devices) based on CuTCNQ metal-organic semiconductors
Publisher: Elsevier BV
Date: 03-2018
Terahertz metasurface for near-field beam conversion
Publisher: Optica Publishing Group
Date: 14-04-2023
DOI: 10.1364/OL.487468
Abstract: A uniform illumination over a screen is crucial for terahertz imaging. As such, conversion from a Gaussian beam to a flattop beam becomes necessary. Most of the current beam conversion techniques rely on bulky multi-lens systems for collimated input and operate in the far-field. We present a single metasurface lens to efficiently convert a quasi-Gaussian beam from the near-field region of a WR-3.4 horn antenna to a flattop beam. The design process is ided into three sections to minimize simulation time, and the conventional Gerchberg–Saxton (GS) algorithm is supplemented with the Kirchhoff–Fresnel diffraction equation. Experimental validation confirms that a flattop beam with an efficiency of 80% has been achieved at 275 GHz. Such high-efficiency conversion is desirable for practical terahertz systems and the design approach can be generally used for beam shaping in the near-field.
Microstructure and dynamics of vacancy-induced nanofilamentary switching network in donor doped SrTiO3-x memristors
Publisher: IOP Publishing
Date: 18-11-2016
DOI: 10.1088/0957-4484/27/50/505210
Abstract: Donor doping of perovskite oxides has emerged as an attractive technique to create high performance and low energy non-volatile analog memories. Here, we examine the origins of improved switching performance and stable multi-state resistive switching in Nb-doped oxygen-deficient amorphous SrTiO
Nanocolumnar Preferentially Oriented PSZT Thin Films Deposited on Thermally Grown Silicon Dioxide
Publisher: Springer Science and Business Media LLC
Date: 11-11-2008
DOI: 10.1007/S11671-008-9197-2
Abstract: We report the first instance of deposition of preferentially oriented, nanocrystalline, and nanocolumnar strontium-doped lead zirconate titanate (PSZT) ferroelectric thin films directly on thermal silicon dioxide. No intermediate seed or activation layers were used between PSZT and silicon dioxide. The deposited thin films have been characterised using a combination of diffraction and microscopy techniques.
Ultrabroadband Plasmonic Absorber for Terahertz Waves
Publisher: Wiley
Date: 28-10-2015
Reversal and pinning of Curie point transformations in thin film piezoelectrics
Publisher: Royal Society of Chemistry (RSC)
Date: 2011
DOI: 10.1039/C0CE00713G
Ultrabroadband reflective polarization convertor for terahertz waves
Publisher: AIP Publishing
Date: 03-11-2014
DOI: 10.1063/1.4901272
Black Phosphorus Nanoflakes Vertically Stacked on MoS2 Nanoflakes as Heterostructures for Photodetection
Publisher: American Chemical Society (ACS)
Date: 12-07-2021
Defining the role of humidity in the ambient degradation of few-layer black phosphorus
Publisher: IOP Publishing
Date: 30-11-2017
Effects of plasma-treatment on the electrical and optoelectronic properties of layered black phosphorus
Publisher: Elsevier BV
Date: 09-0044
Interfacial Resistive Properties of Nickel Silicide Thin Films to Doped Silicon
Publisher: The Electrochemical Society
Date: 2010
DOI: 10.1149/1.3454214
Microstructural and Compositional Analysis of Strontium-Doped Lead Zirconate Titanate Thin Films on Gold-Coated Silicon Substrates
Publisher: Oxford University Press (OUP)
Date: 15-01-2009
DOI: 10.1017/S1431927609090072
Abstract: This article discusses the results of transmission electron microscopy (TEM)-based characterization of strontium-doped lead zirconate titanate (PSZT) thin films. The thin films were deposited by radio frequency magnetron sputtering at 300°C on gold-coated silicon substrates, which used a 15 nm titanium adhesion layer between the 150 nm thick gold film and (100) silicon. The TEM analysis was carried out using a combination of high-resolution imaging, energy filtered imaging, energy dispersive X-ray (EDX) analysis, and hollow cone illumination. At the interface between the PSZT films and gold, an amorphous silicon-rich layer (about 4 nm thick) was observed, with the film composition remaining uniform otherwise. The films were found to be polycrystalline with a columnar structure perpendicular to the substrate. Interdiffusion between the bottom metal layers and silicon was observed and was confirmed using secondary ion mass spectrometry. This occurs due to the temperature of deposition (300°C) being close to the eutectic point of gold and silicon (363°C). The diffused regions in silicon were composed primarily of gold (analyzed by EDX) and were bounded by (111) silicon planes, highlighted by the triangular diffused regions observed in the two-dimensional TEM image.
Experimental demonstration of reflectarray antennas at terahertz frequencies
Publisher: The Optical Society
Date: 30-01-2013
DOI: 10.1364/OE.21.002875
Fabrication of micro-scale single-crystal silicon structures for efficient terahertz magnetic mirror
Publisher: IEEE
Date: 09-2016
Thin film piezoelectric response characterisation using atomic force microscopy with standard contact mode imaging
Publisher: Elsevier BV
Date: 2009
DOI: 10.1016/J.MICRON.2008.01.007
Abstract: This article introduces a technique for observing and quantifying the piezoelectric response of thin films, using standard atomic force microscopes (AFMs). The technique has been developed and verified using strontium-doped lead zirconate titanate (PSZT) thin films, which are known for their high piezoelectric response. Quantification of the electro-mechanical voltage coefficient d(33) (pm/V) is made directly based on the applied peak-to-peak voltage and the corresponding peak-to-peak displacement in the obtained scan image. Under the proposed technique the AFM is configured in contact mode, where the silicon nitride tip is set to follow the film displacement at a single point. A known sinusoidal voltage is applied across the film and the displacement determined as a function of time, rather than the typical AFM measurement of displacement versus tip position. The resulting raster image contains several bands, which are directly related to the AFM scan frequency and the applied sinusoidal voltage and its frequency. Different combinations of the AFM scan frequency and the applied sinusoid frequency have been used to characterise the PSZT thin films, with estimated values of d(33) between 109 and 205 pm/V.
A Photonic Switch Based on a Hybrid Combination of Metallic Nanoholes and Phase-change Vanadium Dioxide
Publisher: Springer Science and Business Media LLC
Date: 23-07-2018
DOI: 10.1038/S41598-018-29476-6
Abstract: A photonic switch is an integral part of optical telecommunication systems. A plasmonic bandpass filter integrated with materials exhibiting phase transition can be used as a thermally reconfigurable optical switch. This paper presents the design and demonstration of a broadband photonic switch based on an aluminium nanohole array on quartz utilising the semiconductor-to-metal phase transition of vanadium dioxide. The fabricated switch shows an operating range over 650 nm around the optical communication C, L, and U band with maximum 20%, 23% and 26% transmission difference in switching in the C band, L band, and U band, respectively. The extinction ratio is around 5 dB in the entire operation range. This architecture is a precursor for developing micron-size photonic switches and ultra-compact modulators for thin film photonics.
Mechanically tolerant fluidic split ring resonators
Publisher: IOP Publishing
Date: 10-06-2016
Elastomeric silicone substrates for terahertz fishnet metamaterials
Publisher: AIP Publishing
Date: 06-02-2012
DOI: 10.1063/1.3665180
Abstract: In this work, we characterize the electromagnetic properties of polydimethylsiloxane (PDMS) and use this as a free-standing substrate for the realization of flexible fishnet metamaterials at terahertz frequencies. Across the 0.2–2.5 THz band, the refractive index and absorption coefficient of PDMS are estimated as 1.55 and 0–22 cm−1, respectively. Electromagnetic modeling, multi-layer flexible electronics microfabrication, and terahertz time-domain spectroscopy are used in the design, fabrication, and characterization of the metamaterials, respectively. The properties of PDMS add a degree of freedom to terahertz metamaterials, with the potential for tuning by elastic deformation or integrated microfluidics.
Specific contact resistivity of Al-NiSi contacts using Cross Kelvin Resistor test structure chains
Publisher: SPIE
Date: 28-12-2005
DOI: 10.1117/12.650699
Flexible terahertz metamaterials for dual-axis strain sensing
Publisher: The Optical Society
Date: 11-06-2013
DOI: 10.1364/OL.38.002104
Investigation of surface crystallites on C54 titanium silicide thin films using transmission electron microscopy
Publisher: IOP Publishing
Date: 18-02-2008
Plasmonic Resonance toward Terahertz Perfect Absorbers
Publisher: American Chemical Society (ACS)
Date: 11-06-2014
DOI: 10.1021/PH500110T
Comparison between an optical dielectric resonator nano-antenna reflectarray and an equivalent dielectric grating reflector
Publisher: IEEE
Date: 07-2013
Elevated Temperature Anodized Nb2O5: A Photoanode Material with Exceptionally Large Photoconversion Efficiencies
Publisher: American Chemical Society (ACS)
Date: 24-04-2012
DOI: 10.1021/NN300408P
Abstract: Here, we demonstrate that niobium pentoxide (Nb(2)O(5)) is an ideal candidate for increasing the efficiencies of dye-sensitized solar cells (DSSCs). The key lies in developing a Nb(2)O(5) crisscross nanoporous network, using our unique elevated temperature anodization process. For the same thicknesses of ∼4 μm, the DSSC based on the Nb(2)O(5) layer has a significantly higher efficiency (∼4.1%) when compared to that which incorporates a titanium dioxide nanotubular layer (∼2.7%). This is the highest efficiency among all of the reported photoanodes for such a thickness when utilizing back-side illumination. We ascribe this to a combination of reduced electron scattering, greater surface area, wider band gap, and higher conduction band edge, as well as longer effective electron lifetimes.
Nanoscale TiO2 dielectric resonator absorbers
Publisher: The Optical Society
Date: 18-07-2016
DOI: 10.1364/OL.41.003391
Strain Modulation of Optoelectronic Properties in Nanolayered Black Phosphorus: Implications for Strain-Engineered 2D Material Systems
Publisher: American Chemical Society (ACS)
Date: 27-07-2022
Dielectric hole lattice for terahertz diffractive optics with high transmission
Publisher: IEEE
Date: 09-2014
Dual Selective Gas Sensing Characteristics of 2D α-MoO3–x via a Facile Transfer Process
Publisher: American Chemical Society (ACS)
Date: 08-10-2019
Abstract: Metal oxide-based gas sensor technology is promising due to their practical applications in toxic and hazardous gas detection. Orthorhombic α-MoO
Design and simulation of a high performance rail-to-rail CMOS op-amp at /spl plusmn/3V supply
Publisher: IEEE
Date: 2006
Nanoscale energy generation characteristics of piezoelectric thin films
Publisher: IEEE
Date: 12-2010
Elemental Analogues of Graphene: Silicene, Germanene, Stanene, and Phosphorene
Publisher: Wiley
Date: 07-11-2014
Abstract: The fascinating electronic and optoelectronic properties of free-standing graphene has led to the exploration of alternative two-dimensional materials that can be easily integrated with current generation of electronic technologies. In contrast to 2D oxide and dichalcogenides, elemental 2D analogues of graphene, which include monolayer silicon (silicene), are fast emerging as promising alternatives, with predictions of high degree of integration with existing technologies. This article reviews this emerging class of 2D elemental materials - silicene, germanene, stanene, and phosphorene--with emphasis on fundamental properties and synthesis techniques. The need for further investigations to establish controlled synthesis techniques and the viability of such elemental 2D materials is highlighted. Future prospects harnessing the ability to manipulate the electronic structure of these materials for nano- and opto-electronic applications are identified.
Second-Order Terahertz Bandpass Frequency Selective Surface With Miniaturized Elements
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 09-2015
Differential work-function enabled bifunctional switching in strontium titanate flexible resistive memories
Publisher: American Chemical Society (ACS)
Date: 24-01-2020
Abstract: Multifunctional electronic memories capable of demonstrating both analog and digital switching on-demand are extremely attractive for miniaturization of electronics without significant drain on energy consumption. Simultaneously translating functionality onto mechanically conformable platforms will further enhance their suitability. Here, we demonstrate the ability to engineer multifunctionality in strontium titanate (STO)-based resistive random-access memories (ReRAM) on a flexible polyimide platform. By utilizing different bottom electrodes of various work functions while the top electrode is fixed, differential work functions are induced in STO, to induce bipolar or complementary switching behaviors whenever required. This work-function difference-induced bifunctional switching on the flexible platform reveals a streamlined route for achieving flexible artificial neural networks, high density integration, and logic operation using a single ReRAM.
Particle tracking simulation of an air channel transistor
Publisher: AIP Publishing
Date: 11-2021
DOI: 10.1063/5.0064051
Abstract: Advances in nanofabrication techniques have underpinned the recent growing interest in vacuum channel transistors due to their ability to showcase ballistic transport and immunity to most radiations. However, the geometry of the electrodes plays an important role in the overall performance and efficiency of the device. Several studies on the geometry of the source electrode have been carried out because of its role in enhancement of the local electric field, which triggers electron tunneling, yet the geometry of the drain electrode has been neglected. Here, we propose a new planar vacuum channel transistor with gold electrodes. Our study shows that the unique geometrical design of the device leads to high collection efficiency. Furthermore, it reveals the importance of the geometry of the drain on device performance. Emission characteristics of the device and the effect of geometrical parameters such as channel length and source geometry on its performance have also been investigated.
Insulator-metal transition in substrate-independent VO2 thin film for phase-change devices
Publisher: Springer Science and Business Media LLC
Date: 20-12-2017
DOI: 10.1038/S41598-017-17937-3
Abstract: Vanadium has 11 oxide phases, with the binary VO 2 presenting stimuli-dependent phase transitions that manifest as switchable electronic and optical features. An elevated temperature induces an insulator–to–metal transition (IMT) as the crystal reorients from a monoclinic state (insulator) to a tetragonal arrangement (metallic). This transition is accompanied by a simultaneous change in optical properties making VO 2 a versatile optoelectronic material. However, its deployment in scalable devices suffers because of the requirement of specialised substrates to retain the functionality of the material. Sensitivity to oxygen concentration and larger-scale VO 2 synthesis have also been standing issues in VO 2 fabrication. Here, we address these major challenges in harnessing the functionality in VO 2 by demonstrating an approach that enables crystalline, switchable VO 2 on any substrate. Glass, silicon, and quartz are used as model platforms to show the effectiveness of the process. Temperature-dependent electrical and optical characterisation is used demonstrating three to four orders of magnitude in resistive switching, % chromic discrimination at infrared wavelengths, and terahertz property extraction. This capability will significantly broaden the horizon of applications that have been envisioned but remained unrealised due to the lack of ability to realise VO 2 on any substrate, thereby exploiting its untapped potential.
Rapid and Selective Biomarker Detection with Conductometric Sensors
Publisher: Wiley
Date: 27-01-2021
Customized Two-Dimensional Nanostructured MoO3 Inks For Spectrally Selective UV Chromic Patches
Publisher: American Chemical Society (ACS)
Date: 08-12-2022
Microstructural investigation of nickel silicide thin films and the silicide–silicon interface using transmission electron microscopy
Publisher: Elsevier BV
Date: 2009
DOI: 10.1016/J.MICRON.2008.01.012
Abstract: This article discusses the results of transmission electron microscopy (TEM)-based investigation of nickel silicide (NiSi) thin films grown on silicon. Nickel silicide is currently used as the CMOS technology standard for local interconnects and in electrical contacts. Films were characterized with a range of TEM-based techniques along with glancing angle X-ray diffraction. The nickel silicide thin films were formed by vacuum annealing thin films of nickel (50 nm) deposited on (100) silicon. The cross-sectional s les indicated a final silicide thickness of about 110 nm. This investigation studied and reports on three aspects of the thermally formed thin films: the uniformity in composition of the film using jump ratio maps the nature of the interface using high resolution imaging and the crystalline orientation of the thin films using selected-area electron diffraction (SAED). The analysis highlighted uniform composition in the thin films, which was also substantiated by spectroscopy techniques an interface exhibiting the desired abrupt transition from silicide to silicon and desired and preferential crystalline orientation corresponding to stoichiometric NiSi, supported by glancing angle X-ray diffraction results.
Correlation between nanomechanical and piezoelectric properties of thin films: An experimental and finite element study
Publisher: Elsevier BV
Date: 2013
Terahertz Reflectarrays and Nonuniform Metasurfaces
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-2017
Terahertz and optical Dielectric Resonator Antennas: Potential and challenges for efficient designs
Publisher: IEEE
Date: 04-2016
Elastomer-based pneumatic switch for radio frequency microdevices
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-2012
Low-temperature deposition of high-response piezoelectric thin films
Publisher: Elsevier BV
Date: 07-2010
Broadband and wide-angle reflective linear polarization converter for terahertz waves
Publisher: AIP Publishing
Date: 09-2019
DOI: 10.1063/1.5116149
Nicotine Sensors for Wearable Battery-Free Monitoring of Vaping
Publisher: American Chemical Society (ACS)
Date: 08-12-2022
DOI: 10.1021/ACSSENSORS.1C01633
Abstract: Nicotine, an addictive substance in tobacco products and electronic cigarettes (e-cigs), is recognized for increasing the risk of cardiovascular and respiratory disorders. Careful real-time monitoring of nicotine exposure is critical in alleviating the potential health impacts of not just smokers but also those exposed to second-hand and third-hand smoke. Monitoring of nicotine requires suitable sensing material to detect nicotine selectively and testing under free-living conditions in the standard environment. Here, we experimentally demonstrate a vanadium dioxide (VO
Nickel silicide and titanium silicide formation: a comparison
Publisher: SPIE
Date: 27-12-2006
DOI: 10.1117/12.695939
Meta-atom microfluidic sensor for measurement of dielectric properties of liquids
Publisher: AIP Publishing
Date: 07-03-2017
DOI: 10.1063/1.4978012
Abstract: High sensitivity microwave frequency microfluidic sensing is gaining popularity in chemical and biosensing applications for evaluating the dielectric properties of liquid s les. Here, we show that a tiny microfluidic channel positioned in the gaps of a dual-gap meta-atom split-ring resonator can exploit the electric field sensitivity to predict the dielectric properties of liquid s les. Employing an empirical relation between resonant characteristics of the fabricated sensor and the complex permittivity of water-ethanol or water-methanol mixtures produces good congruence to standardized values from the literature. This microfluidic sensor offers a potential lab-on-chip solution for liquid dielectric characterization without external electrical connections.
Ultra-wideband tri-layer transmissive linear polarization converter for terahertz waves
Publisher: AIP Publishing
Date: 04-2020
DOI: 10.1063/1.5144115
Two-dimensional molybdenum trioxide and dichalcogenides
Publisher: Wiley
Date: 02-04-2013
Dielectrophoresis-based microfluidic platforms for cancer diagnostics
Publisher: AIP Publishing
Date: 2018
DOI: 10.1063/1.5010158
Abstract: The recent advancement of dielectrophoresis (DEP)-enabled microfluidic platforms is opening new opportunities for potential use in cancer disease diagnostics. DEP is advantageous because of its specificity, low cost, small s le volume requirement, and tuneable property for microfluidic platforms. These intrinsic advantages have made it especially suitable for developing microfluidic cancer diagnostic platforms. This review focuses on a comprehensive analysis of the recent developments of DEP enabled microfluidic platforms sorted according to the target cancer cell. Each study is critically analyzed, and the features of each platform, the performance, added functionality for clinical use, and the types of s les, used are discussed. We address the novelty of the techniques, strategies, and design configuration used in improving on existing technologies or previous studies. A summary of comparing the developmental extent of each study is made, and we conclude with a treatment of future trends and a brief summary.
Skin color-specific and spectrally-selective naked-eye dosimetry of UVA, B and C radiations
Publisher: Springer Science and Business Media LLC
Date: 25-09-2018
DOI: 10.1038/S41467-018-06273-3
Abstract: Spectrally–selective monitoring of ultraviolet radiations (UVR) is of paramount importance across erse fields, including effective monitoring of excessive solar exposure. Current UV sensors cannot differentiate between UVA, B, and C, each of which has a remarkably different impact on human health. Here we show spectrally selective colorimetric monitoring of UVR by developing a photoelectrochromic ink that consists of a multi-redox polyoxometalate and an e − donor. We combine this ink with simple components such as filter paper and transparency sheets to fabricate low-cost sensors that provide naked-eye monitoring of UVR, even at low doses typically encountered during solar exposure. Importantly, the erse UV tolerance of different skin colors demands personalized sensors. In this spirit, we demonstrate the customized design of robust real-time solar UV dosimeters to meet the specific need of different skin phototypes. These spectrally–selective UV sensors offer remarkable potential in managing the impact of UVR in our day-to-day life.
RF magnetron sputtered perovskite-oriented PSZT thin films on gold for piezoelectric and ferroelectric transducers
Publisher: Institution of Engineering and Technology (IET)
Date: 2006
DOI: 10.1049/EL:20063422
Design and implementation of terahertz reflectarray
Publisher: IEEE
Date: 09-2012
Elastomeric composites for flexible microwave substrates
Publisher: AIP Publishing
Date: 28-03-2016
DOI: 10.1063/1.4945037
Abstract: Manipulating dielectric properties of polydimethylsiloxane (PDMS) is an important consideration for flexible, low-loss device design. This paper presents a method for reducing dielectric loss (tan δ) by forming PDMS composites loaded with various concentrations of either alumina (Al2O3) or polytetrafluoroethylene (PTFE) particles. The structural, mechanical, and electrical properties of the composites are investigated. Theoretical mixing models were used to predict the relative permittivity (εr) of PDMS composites, and good similarity with the measured εr was observed. The incorporation of either low dielectric loss filler in the PDMS matrix (up to 50 wt. % filler loading) is shown to reduce the dielectric loss while maintaining the flexibility of the host matrix. The fillers can also control the permittivity of the composite, either increasing or decreasing relative permittivity from that of PDMS. Interestingly, a strain of ∼500% can be applied to 15 wt. % PDMS/PTFE composites, compared with ∼350% for pure PDMS.
Influence of oxygen partial pressure on the composition and orientation of strontium-doped lead zirconate titanate thin films
Publisher: Elsevier BV
Date: 2009
DOI: 10.1016/J.MICRON.2007.12.009
Abstract: The influence of oxygen partial pressure during the deposition of piezoelectric strontium-doped lead zirconate titanate thin films is reported. The thin films have been deposited by RF magnetron sputtering in an atmosphere of high purity argon and oxygen (in the ratio of 9:1), on platinum-coated silicon substrates (heated to 650 degrees C). The influence of oxygen partial pressure is studied to understand the manner in which the stoichiometry of the thin films is modified, and to understand the influence of stoichiometry on the perovskite orientation. This article reports on the results obtained from films deposited at oxygen partial pressures of 1-5 mTorr. The thin films have been studied using a combination of X-ray photoelectron spectroscopy (XPS), glancing angle X-ray diffraction (GA-XRD), and atomic force microscopy (AFM). XPS analysis highlights the marked influence of variations in oxygen pressure during sputtering, observed by variations in oxygen concentration in the thin films, and in some cases by the undesirable decrease in lead concentration in the thin films. GA-XRD is used to study the relative variations in perovskite peak intensities, and has been used to determine the deposition conditions to attain the optimal combination of stoichiometry and orientation. AFM scans show the marked influence of the oxygen partial pressure on the film morphology.
Characterisation of nickel silicide thin films by spectroscopy and microscopy techniques
Publisher: Elsevier BV
Date: 2009
DOI: 10.1016/J.MICRON.2007.12.008
Abstract: This article discusses the formation and detailed materials characterisation of nickel silicide thin films. Nickel silicide thin films have been formed by thermally reacting electron beam evaporated thin films of nickel with silicon. The nickel silicide thin films have been analysed using Auger electron spectroscopy (AES) depth profiles, secondary ion mass spectrometry (SIMS), and Rutherford backscattering spectroscopy (RBS). The AES depth profile shows a uniform NiSi film, with a composition of 49-50% nickel and 51-50% silicon. No oxygen contamination either on the surface or at the silicide-silicon interface was observed. The SIMS depth profile confirms the existence of a uniform film, with no traces of oxygen contamination. RBS results indicate a nickel silicide layer of 114 nm, with the simulated spectra in close agreement with the experimental data. Atomic force microscopy and transmission electron microscopy have been used to study the morphology of the nickel silicide thin films. The average grain size and average surface roughness of these films was found to be 30-50 and 0.67 nm, respectively. The film surface has also been studied using Kikuchi patterns obtained by electron backscatter detection.
Nanoscale Resistive Switching in Amorphous Perovskite Oxide ( a- SrTiO 3 ) Memristors
Publisher: Wiley
Date: 26-08-2014
Surface morphology and stress analysis of piezoelectric strontium-doped lead zirconate titanate thin films
Publisher: SPIE
Date: 27-12-2006
DOI: 10.1117/12.695941
Mechanically Tunable High Refractive-Index Contrast TiO2-PDMS Gratings
Publisher: Wiley
Date: 17-08-2015
Spectral and angular characteristics of dielectric resonator metasurface at optical frequencies
Publisher: AIP Publishing
Date: 10-11-2014
DOI: 10.1063/1.4901735
Abstract: The capability of manipulating light at subwavelength scale has fostered the applications of flat metasurfaces in various fields. Compared to metallic structure, metasurfaces made of high permittivity low-loss dielectric resonators hold the promise of high efficiency by avoiding high conductive losses of metals at optical frequencies. This letter investigates the spectral and angular characteristics of a dielectric resonator metasurface composed of periodic sub-arrays of resonators with a linearly varying phase response. The far-field response of the metasurface can be decomposed into the response of a single grating element (sub-array) and the grating arrangement response. The analysis also reveals that coupling between resonators has a non-negligible impact on the angular response. Over a wide wavelength range, the simulated and measured angular characteristics of the metasurface provide a definite illustration of how different grating diffraction orders can be selectively suppressed or enhanced through antenna sub-array design.
Electrically Activated UV-A Filters Based on Electrochromic MoO3–x
Publisher: American Chemical Society (ACS)
Date: 23-03-2020
Mechanically Tunable Dielectric Resonator Metasurfaces at Visible Frequencies
Publisher: American Chemical Society (ACS)
Date: 02-12-2016
Abstract: Devices that manipulate light represent the future of information processing. Flat optics and structures with subwavelength periodic features (metasurfaces) provide compact and efficient solutions. The key bottleneck is efficiency, and replacing metallic resonators with dielectric resonators has been shown to significantly enhance performance. To extend the functionalities of dielectric metasurfaces to real-world optical applications, the ability to tune their properties becomes important. In this article, we present a mechanically tunable all-dielectric metasurface. This is composed of an array of dielectric resonators embedded in an elastomeric matrix. The optical response of the structure under a uniaxial strain is analyzed by mechanical-electromagnetic co-simulations. It is experimentally demonstrated that the metasurface exhibits remarkable resonance shifts. Analysis using a Lagrangian model reveals that strain modulates the near-field mutual interaction between resonant dielectric elements. The ability to control and alter inter-resonator coupling will position dielectric metasurfaces as functional elements of reconfigurable optical devices.
Dielectric resonator nanoantennas: A review of the theoretical background, design examples, prospects, and challenges
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-2017
Strain Engineering of Wave‐like Nanofibers for Dynamically Switchable Adhesive/Repulsive Surfaces
Publisher: Wiley
Date: 07-12-2015
Nickel silicide thin films as masking and structural layers for silicon bulk micro-machining by potassium hydroxide wet etching
Publisher: IOP Publishing
Date: 24-07-2008
Lattice Guiding for Low Temperature Crystallization of Rhombohedral Perovskite-Structured Oxide Thin Films
Publisher: American Chemical Society (ACS)
Date: 18-12-2009
DOI: 10.1021/CG901165J
Terahertz reflectarray as a polarizing beam splitter
Publisher: The Optical Society
Date: 23-06-2014
DOI: 10.1364/OE.22.016148
Electron Emission Devices for Energy‐Efficient Systems
Publisher: Wiley
Date: 08-2019
Terahertz Magnetic Mirror Realized with Dielectric Resonator Antennas
Publisher: Wiley
Date: 09-10-2015
Abstract: Single-crystal silicon is bonded to a metal-coated substrate and etched in order to form an array of microcylinder passive terahertz dielectric resonator antennas (DRAs). The DRAs exhibit a magnetic response, and hence the array behaves as an efficient artificial magnetic conductor (AMC), with potential for terahertz antenna and sensing applications.
Efficiency and Scalability of Dielectric Resonator Antennas at Optical Frequencies
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 08-2014
Polarization-insensitive terahertz spoof localized surface plasmon-induced transparency based on lattice rotational symmetry
Publisher: AIP Publishing
Date: 06-07-2020
DOI: 10.1063/5.0009785
Abstract: In recent years, metasurfaces enabling a slow light effect in the terahertz band have seen considerable achievement. However, most of these advances demonstrated so far are polarization sensitive. In this work, we demonstrate polarization-insensitive terahertz slow light at spoof surface plasmon-induced transparency windows. Two types of metasurfaces based on different lattice layouts, a C2 and a C4 lattice symmetry, are compared. On the one hand, the metasurface with C2 lattice symmetry displayed a 5 ps slow light effect in a transparency window around 0.3 THz. On the other hand, the metasurface with a C4 lattice layout achieves a maximum of 28 ps slow light at 0.3 THz. The coupling coefficient and the d ing ratio in the transparency window in the metasurface with C4 lattice symmetry are 5 times higher than in the metasurface with C2 lattice layout. Two eigenmode mode constructive interference introduces a positive group delay in the transparency window in the metasurface with C4 lattice symmetry, whereas the superposition of two eigenmodes in the metasurface with C2 lattice symmetry forms the transparency window without distinct coupling. Our results show that the point group symmetry or lattice structure of a metasurface has a huge impact on the group velocity of terahertz pulses and therefore introduces flexibility in the design of polarization-insensitive slow light devices for terahertz telecommunication application.
Reduced impurity-driven defect states in anodized nanoporous Nb2O5: the possibility of improving performance of photoanodes
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3CC42998A
Abstract: Anodized nanoporous Nb2O5 films are synthesized using two different types of electrolyte compositions onto transparent conductive glasses and their impurities induced during the anodization process are assessed. These films are incorporated as photoanodes in dye sensitized solar cells (DSSCs). The one with no traces of impurity-driven defects exhibits higher current density and longer electron lifetimes, and consequently, an improvement in photoconversion efficiencies compared to the one that contains impurities.
Surface Morphology Induced Localized Electric Field and Piezoresponse Enhancement in Nanostructured Thin Films
Publisher: American Chemical Society (ACS)
Date: 27-01-2011
DOI: 10.1021/NN103561U
Abstract: Nanostructured piezoelectric and ferroelectric thin films are being increasingly used in sensing and actuating microdevices. In this work, we report the experimental discovery of localized electric field enhancement in nanocolumnar piezoelectric thin films and its significant impact on piezoresponse. The magnitude of electric field enhancement is associated with nonflat surface morphologies and is in agreement with theoretical and finite element models. The influence of this surface morphology induced enhancement on piezoresponse is demonstrated using phase field simulations, which also illustrates surface morphology induced strain enhancement. The observed enhancement can be effectively harnessed to improve the sensitivity of related piezoelectric thin film applications.
Inducing tunable switching behavior in a single memristor
Publisher: Elsevier BV
Date: 06-2018
In situ nanoindentation: Probing nanoscale multifunctionality
Publisher: Elsevier BV
Date: 2013
Metal-Air Field Emission Devices - Nano Electrode Geometries Comparison of Performance and Stability.
Publisher: Wiley
Date: 12-09-2022
Abstract: Air-channel devices have a special advantage due to the promise of vacuum-like ballistic transport in air, radiation insensitivity, and nanoscale size. Here, achieving high current at low voltage along with considerable mechanical stability is a primary issue. The comparative analysis of four planar and metallic electrode-pair geometries at 10 nm channel length is presented. The impact of nano-electrode-pair geometries on overall device performance is investigated. Air-channel devices are operated at the ultra-low voltage of 5 mV to demonstrate the device dynamics of air-channel devices at low power. Investigations focus on the direct tunneling (DT) mechanism which is dominant in the low-voltage regime. Comparative analysis of different electrode-pair geometries reveals two orders of magnitude increment in the current just by modulating the electrode-pair structure. Theoretical analysis suggests that the emission current is directly related to the active junction area within the metal-air-metal interface at the direct tunneling regime. The geometry-dependent mechanical stability of different electrode pairs is compared by imaging biasing triggered nanoscale structural changes and pulsed biasing stress analysis. The results and claims are confirmed and consolidated with the statistical analysis. Experimental investigations provide strong directions for high-performance and stable devices. In-depth theoretical discussions will enable the accurate modeling of emerging low-power, high-speed, radiation-hardened nanoscale vacuum electronics.
Influence of nano-graphite platelet concentration on onset of crystalline degradation in polylactide composites
Publisher: Elsevier BV
Date: 05-2012
Alkali ratio control for lead-free piezoelectric thin films utilizing elemental diffusivities in RF plasma
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3CE40508G
In situ investigation of thermally influenced phase transformations in (pb0.92sr0.08) (zr0.65ti0.35)o3 thin films using micro-raman spectroscopy
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 02-2009
Transparent amorphous strontium titanate resistive memories with transient photo-response
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7NR04372D
Abstract: Highly transparent SrTiO 3 resistive memories with transient response to optical excitations are demonstrated and the evolution of oxygen vacancies with the location of a conductive filament is optically mapped.
Characterization of C54 titanium silicide thin films by spectroscopy, microscopy and diffraction
Publisher: IOP Publishing
Date: 16-08-2007
MnO2 -based thermopower wave sources with exceptionally large output voltages
Publisher: American Chemical Society (ACS)
Date: 25-04-2013
DOI: 10.1021/JP401731B
Dielectric-resonator metasurfaces for broadband terahertz quarter- and half-wave mirrors
Publisher: The Optical Society
Date: 22-05-2018
DOI: 10.1364/OE.26.014392
The effect of post-deposition cooling rate on the orientation of piezoelectric (Pb0.92Sr0.08)(Zr0.65Ti0.35)O3thin films deposited by RF magnetron
Publisher: IOP Publishing
Date: 18-07-2006
Reversible resistive switching behaviour in CVD grown, large area MoO: X
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C8NR04407D
Abstract: Reversible resistive switching behaviour is observed in MoO x memory devices, at relatively low set/reset voltages, with switching ratios exceeding 10 3 .
Terahertz sensing of 7 nm dielectric film with bound states in the continuum metasurfaces
Publisher: AIP Publishing
Date: 07-10-2019
DOI: 10.1063/1.5110383
Abstract: The fingerprint spectral response of several materials with terahertz electromagnetic radiation indicates that terahertz technology is an effective tool for sensing applications. However, sensing few nanometer thin-films of dielectrics with much longer terahertz waves (1 THz = 0.3 mm) is challenging. Here, we demonstrate a quasibound state in the continuum (BIC) resonance for sensing of a nanometer scale thin analyte deposited on a flexible metasurface. The large sensitivity originates from the strong local field confinement of the quasi-BIC Fano resonance state and extremely low absorption loss of a low-index cyclic olefin copolymer substrate. A minimum thickness of 7 nm thin-film of germanium is sensed on the metasurface, which corresponds to a deep subwavelength scale of λ/43 000, where λ is the resonance wavelength. The low-loss, flexible, and large mechanical strength of the quasi-BIC microstructured metamaterial sensor could be an ideal platform for developing ultrasensitive wearable terahertz sensors.
Dielectric resonator nanoantennas at visible frequencies
Publisher: The Optical Society
Date: 11-01-2013
DOI: 10.1364/OE.21.001344
Strain-resistance relationship in gold conductors for elastomeric-based flexible devices
Publisher: SPIE
Date: 21-12-2011
DOI: 10.1117/12.903187
Nanocomposite carbon-PDMS membranes for gas separation
Publisher: Elsevier BV
Date: 2012
Passive electric monopole array for terahertz surface wave launcher
Publisher: IEEE
Date: 08-2015
Generating strong room-temperature photoluminescence in black phosphorus using organic molecules
Publisher: IOP Publishing
Date: 30-10-2019
Design and analysis of a metasurface for supporting spoof surface plasmon polaritons
Publisher: IEEE
Date: 12-2012
Dielectric Resonator Reflectarray as High-Efficiency Nonuniform Terahertz Metasurface
Publisher: American Chemical Society (ACS)
Date: 19-05-2016
Metallic and dielectric resonators in broadband half-wave mirrors for terahertz frequencies
Publisher: IEEE
Date: 02-2018
Infrared Non‐Invasive Exhaled Biomarker Sensing: A Review
Publisher: Wiley
Date: 07-09-2023
Atomically thin layers of MoS 2 via a two step thermal evaporation-exfoliation method
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C1NR10803D
Abstract: Two dimensional molybdenum disulfide (MoS(2)) has recently become of interest to semiconductor and optic industries. However, the current methods for its synthesis require harsh environments that are not compatible with standard fabrication processes. We report on a facile synthesis method of layered MoS(2) using a thermal evaporation technique, which requires modest conditions. In this process, a mixture of MoS(2) and molybdenum dioxide (MoO(2)) is produced by evaporating sulfur powder and molybdenum trioxide (MoO(3)) nano-particles simultaneously. Further annealing in a sulfur-rich environment transforms majority of the excess MoO(2) into layered MoS(2). The deposited MoS(2) is then mechanically exfoliated into minimum resolvable atomically thin layers, which are characterized using micro-Raman spectroscopy and atomic force microscopy. Furthermore Raman spectroscopy is employed to determine the effect of electrochemical lithium ion exposure on atomically thin layers of MoS(2).
Ambient Protection of Few-Layer Black Phosphorus via Sequestration of Reactive Oxygen Species
Publisher: Wiley
Date: 12-05-2017
Abstract: Few-layer black phosphorous (BP) has emerged as a promising candidate for next-generation nanophotonic and nanoelectronic devices. However, rapid ambient degradation of mechanically exfoliated BP poses challenges in its practical deployment in scalable devices. To date, the strategies employed to protect BP have relied upon preventing its exposure to atmospheric conditions. Here, an approach that allows this sensitive material to remain stable without requiring its isolation from the ambient environment is reported. The method draws inspiration from the unique ability of biological systems to avoid photo-oxidative damage caused by reactive oxygen species. Since BP undergoes similar photo-oxidative degradation, imidazolium-based ionic liquids are employed as quenchers of these damaging species on the BP surface. This chemical sequestration strategy allows BP to remain stable for over 13 weeks, while retaining its key electronic characteristics. This study opens opportunities to practically implement BP and other environmentally sensitive 2D materials for electronic applications.
Silicon terahertz resonators
Publisher: IEEE
Date: 02-2016
RF magnetron sputter deposition and analysis of strontium-doped lead zirconate titanate thin films
Publisher: SPIE
Date: 28-12-2005
DOI: 10.1117/12.668052
Mechanically tunable terahertz metamaterials
Publisher: AIP Publishing
Date: 25-03-2013
DOI: 10.1063/1.4773238
Abstract: Electromagnetic device design and flexible electronics fabrication are combined to demonstrate mechanically tunable metamaterials operating at terahertz frequencies. Each metamaterial comprises a planar array of resonators on a highly elastic polydimethylsiloxane substrate. The resonance of the metamaterials is controllable through substrate deformation. Applying a stretching force to the substrate changes the inter-cell capacitance and hence the resonance frequency of the resonators. In the experiment, greater than 8% of the tuning range is achieved with good repeatability over several stretching-relaxing cycles. This study promises applications in remote strain sensing and other controllable metamaterial-based devices.
Broadband plasmonic terahertz absorber based on silicon cross structures
Publisher: IEEE
Date: 09-2014
Terahertz near-field imaging of dielectric resonators
Publisher: The Optical Society
Date: 13-02-2017
DOI: 10.1364/OE.25.003756
Visible-Blind UV Imaging with Oxygen-Deficient Zinc Oxide Flexible Devices
Publisher: Wiley
Date: 26-10-2015
Vanadium Dioxide-Based Miniaturized Thermal Sensors: Humidity Effects on Phase Change and Sensitivity
Publisher: American Chemical Society (ACS)
Date: 10-11-2022
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