W. Włodarski

RMIT University

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Kourosh Kalantar‐zadeh

UNSW Sydney

119

Giorgio Sberveglieri

University of Brescia

K. Galatsis

University of California, Los Angeles

Elisabetta Comini

University of Brescia

Abu Z. Sadek

Melbourne Centre for Nanofabrication

Mahnaz Shafiei

Swinburne University of Technology

Adrian Trinchi

CSIRO Manufacturing

Samuel J. Ippolito

RMIT University

J. Yu

Chinese Academy of Medical Sciences & Peking Union Medical College

Richard B. Kaner

California NanoSystems Institute

Cooperative Institutions

RMIT University

105

MIT University

Chinese Academy of Sciences

The Royal Melbourne Hospital

RMIT Europe

National Research Council

University of Melbourne

CSIRO Manufacturing

Shanghai Institute of Ceramics

Materials Science & Engineering

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A highly sensitive room temperature humidity sensor based on 2D-WS2 nanosheets

FlatChem (2018)

Salvatore Gianluca Leonardi W. Włodarski Yuncang Li Nicola Donato Zdeněk Sofer

Exfoliation joint

Nanomaterials

10.1016/j.flatc.2018.05.001

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Citations (36)

Nanorod based Schottky contact gas sensors in reversed bias condition

Nanotechnology (2010)

J. Yu Samuel J. Ippolito W. Włodarski Michael S. Strano Kourosh Kalantar‐zadeh

There has been significant interest in using electronically contacted nanorod or nanotube arrays as gas sensors, whereby an adsorbate modifies either the impedance or the Fermi level of the array, enabling detection. Typically, such arrays demonstrate the I–V curves of a Schottky diode that is formed using a metal–semiconductor junction with rectifying characteristics. We show in this work that nanostructured Schottky diodes have a functionally different response, characteristic of the large electric field induced by the size scale of the array. Specifically, they are characterized by a low reverse breakdown voltage. As a result, the reverse bias current becomes a strong function of the applied voltage. In this work, for the first time, we model this unique feature by describing the enhancement effect of high aspect ratio nanostructures on the I–V characteristics of a Schottky diode. A Pt/ZnO/SiC nanostructured Schottky diode is fabricated to verify the theoretical equations presented. The gas sensing properties of the Schottky diode in reversed bias is investigated and it is shown that the theoretical calculations are in excellent agreement with measurements.

Nanorod

Metal–semiconductor junction

Biasing

10.1088/0957-4484/21/26/265502

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Citations (107)

Hydrogen gas sensors based on Pt/Nanostructured metal-oxide/SiC Schottky diodes: a review

International Conference on Nanoscience and Nanotechnology (2012)

Mahnaz Shafiei J. Yu Nunzio Motta Andrea Capasso Kourosh Kalantar‐zadeh

Wide-bandgap semiconductor

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WO3-Au nanocomposite thin films as optical gas sensors

Enrico Della Gaspera Alessandro Martucci Mohd Hanif Yaacob Junfei Ou Kourosh Kalantar‐zadeh

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Optical and conductivity dependence on doping concentration of polyaniline nanofibers

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE (2007)

Haitham Abdul Jabbar Qasim Abu Z. Sadek R. Arsat W. Włodarski Iouri Belski

Polyaniline (PANI) is one of the most studied conducting polymers. Obtained in its conducting form (known as "emeraldine salt") by chemical or electrochemical oxidation of aniline in aqueous acidic medium, this polymer manifests an array of attractive properties. In our work, we investigate the properties of PANI in the form of nanofibers and establish the relationship between the level of doping, optical properties and the conductivity. Two methodologies, chemical and electro-chemical polymerization were used to deposit PANI. In former, dedoped PANI was deposited as a thin film on the glass substrate which was then doped with different concentrations of hydrochloric acid (HCl) to observe the change in conductivity and color. UV-Visible spectra (transmittance and absorbance) of the films were acquired and their conductivities were measured using a four-probe setup. In the latter method, PANI in the emeraldine salt form were deposited on ITO glass using an electrolytic cell. The voltage, temperature and electrolytic environment were varied to analyze the effect of change of doping levels on the optical and electrical properties of PANI. Surface electron microscope images were also taken which showed the nanofibers possessing circular cross sections in the order of 30-60 nm.

Polyaniline nanofibers

Absorbance

Hydrochloric acid

10.1117/12.758331

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Citations (4)

Microstructural characterization of MoO3–TiO2 nanocomposite thin films for gas sensing

Sensors and Actuators B Chemical (2001)

Y.X Li K. Galatsis W. Włodarski M. Passacantando S. Santucci

Brookite

Orthorhombic crystal system

Nanocrystalline material

10.1016/s0925-4005(01)00668-2

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Citations (40)

Study of novel Love mode surface acoustic wave filters

Kourosh Kalantar‐zadeh W. Włodarski K. Galatsis Anthony S. Holland

Novel Love mode filters based on ZnO and SiO/sub 2//90/spl deg/ rotated ST-cut quartz crystal structure were fabricated. A comprehensive study was carried out to show the capabilities of such filters. The periodicity of the fingers is 50 /spl mu/m and the thickness of the SiO/sub 2/ and ZnO layers ranges from 0.2 to 7.2 /spl mu/m. Electromechanical coupling coefficient, capacitance per unit wavelengths of finger pairs and temperature coefficient of frequency are studied in terms of thickness of the wave-guiding layers.

Electromechanical coupling coefficient

Temperature coefficient

Crystal (programming language)

Mode (computer interface)

10.1109/freq.2002.1075860

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Citations (4)

Defect detection systems for enameled copper wire, cable, and optical fiber: state of the art and current trends

IEEE Electrical Insulation Magazine (1999)

Hamdy Abd El Hamid W. Włodarski Frank Brennan

International competition among copper wire suppliers increased the demand for automatic surface inspection equipment. The authors critically review a range of existing surface inspection techniques and describe preliminary results on a new system.

Copper wire

Optical fiber cable

10.1109/57.806376

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Citations (1)

A finite element approach for 3-dimensional simulation of layered acoustic wave transducers

Samuel J. Ippolito Kourosh Kalantar‐zadeh David A. Powell W. Włodarski

Layered Surface Acoustic Wave (SAW) transducers were fabricated and modelled by finite-element method. A comparison of the frequency response of the measured devices and simulated structures are presented. The transducer structure is based on a two-port delay line, employing x-cut, y-propagating lithium niobate (LiNbO/sub 3/) substrate and a thin film zinc oxide (ZnO) guiding layer. A finite-element approach was employed to simulate a 3-dimensional version of the fabricated device. A transient analysis was conducted, where electrical and mechanical boundary values were applied. Simulation results show good agreement with experimental results, indicating that a finite-element approach is appropriate for modelling layered SAW transducers.

Interdigital transducer

10.1109/commad.2002.1237309

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Citations (13)

Sol–gel prepared MoO3–WO3 thin-films for O2 gas sensing

Sensors and Actuators B Chemical (2001)

K. Galatsis Y.X Li W. Włodarski Kourosh Kalantar‐zadeh

Tungsten trioxide

Molybdenum trioxide

Orthorhombic crystal system

Mixed oxide

10.1016/s0925-4005(01)00738-9

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Citations (116)