- Date:
- 2009-2016
- Theme:
- Nanoelectronics
- Funding:
- Royal Society (Brian Mercer feasibility award)
The use of electrodeposited PdNi/Si Schottky barriers as low power Hydrogen sensors is investigated. The Palladium content of the film causes the Hydrogen molecules to dissociate and be absorbed by the film, changing the metal work function and Schottky barrier current. In this work we show that electrodeposited Pd(Ni)/Si Schottky barriers exhibit very low reverse bias currents compared to evaporated Schottky diodes. The Schottky diodes were fabricated on 0.5ââ¬â1.5 Ohmcm (100) n-type Si by electrodeposition of PdNi followed by evaporation of aluminium contact pads. Electrical measurements at different Hydrogen pressures were performed on back-to-back Schottky diodes in a vacuum chamber using pure nitrogen and a 5% hydrogenââ¬ânitrogen mixture. Very low currents of 1 nA were measured in the absence of hydrogen. Large increases in the currents, up to a factor of 100, were observed upon exposure to different hydrogen partial pressures. A back-to-back configuration forms a device that draws extremely low power when idle. The low idle current, simplicity of the fabrication process and ability to easily integrate with conventional electronics proves the suitability of electrodeposited PdNiââ¬âSi Schottky barriers as low power hydrogen sensors.
Primary investigators
- Kees De Groot
- ld4e09
- xl2
Secondary investigator
- Chavagnac (Toulouse, France)
- Date:
- 2010-2021
- Themes:
- Nanoelectronics, Nanophotonics and Biomimetics
- Funding:
- EPSRC (EP/J011797/1), H2020 (687303), H2020
Miniaturization of optical components for on-chip integration of electronic and photonic functionalities is one of the new frontiers with the promise of enabling a next generation of integrated optoelectronic circuits. A particularly fascinating prospect is the achievement of an optical analogue of the electronic transistor, which forms the building block of our computers. Our approach involves a nanoscale version of a radiowave antenna, the plasmonic nanoantenna. Plasmonic antennas are designed to overcome the diffraction limit of light and to focus light into a nanometer-sized antenna 'feed' gap.
In our first studies supported by EPSRC we have proposed a variety of devices exploiting hybrid interactions of a nanoantenna with an active substrate. Here, we aim to launch a full-scale investigation of such hybrid antenna devices including various geometries and metal oxide substrates, where the plasmonic antenna will be exploited as a nanoscale sensitizer for the active substrate. Integration of a nanoantenna switches with a nanoelectronic transistor will yield a new class of optoelectronic devices: the nanoantenna MOSFET.
The proposed optically and electrically controlled nanoantenna devices are of enormous interest as a bridge for on-chip control of electrical and optical information. In addition, ultrafast active control of local fields and antenna radiation patterns will enable new applications in nonlinear optics, Raman sensors, and optical quantum information technology.
Primary investigators
- Otto Muskens (Physics)
- Kees De Groot
- Harold Chong
- Sun Kai
- Yudong Wang
Secondary investigators
- Christoph Riedel
- Wei Xiao
Associated research group
- Sustainable Electronic Technologies
- Date:
- 2010-2016
- Funding:
- EPSRC
We recently carried out optical experiments that demonstrated RT spin transport and extraction through Ge for the first time,1 based on structure with Ge grown epitaxial on GaAs and an electrodeposited Ni/Ge Schottky contact. Here, we propose to build upon that work and use the Si-Ge system to its full extent, through delta doping and bandstructure-engineering to maximize spin transparency of the electrical contacts and using strain and low dimensionality to enhance coherent transport in the channel. The culmination of this project should be the exciting prospect of the elusive two-terminal semiconductor spin valve operating at RT and an early demonstration of spin modulation by a gate electrode in such a device.
Primary investigators
- Kees De Groot
- xl2
Partners
- Warwick University
- Cambridge University
Associated research group
- Nano Research Group
- Date:
- 2010-2021
- Themes:
- Nanoelectronics, Quantum Electronics and Spintronics, Materials & Technology
- Funding:
- EPSRC (EP/I010890/1), EPSRC (EP/N035437/1)
This project is concerned with developing non-aqueous electrochemical methods and suitably tailored reagents to facilitate spatially selective electrodeposition of binary (e.g. In2(Se,Te)3, Sb2(Se,Te)3, Ge(Se,Te)) and ternary chalcogenide materials (e.g. Ge2Sb2Te5, doped Sb2Te3) for applications in solid-state phase change memory (PCM). The key objectives are to demonstrate successful selective deposition of the target materials inside nano-scale (down to 2 nm) confined cell structures and to establish the effect of down-scaling pore size on the deposition process. Successful electrodeposition of well-defined compound semiconductor alloy compositions of these types will provide a significant new enabling technology which could also have a major impact on the other applications requiring semiconductor alloy deposition on a nano-scale.
Primary investigators
- Kees De Groot
- Phil Bartlett (Chemistry)
- Gill Reid (Chemistry)
- Andrew Hector (Chemistry)
- David Smith (Physics)
- Ruomeng Huang
- Yasir Noori
Secondary investigators
- Katarina Cicvaric
- Daniel Newbrook
Partners
- University of Warwick
- University of Nottingham
Associated research group
- Sustainable Electronic Technologies
- Date:
- 2012-2016
- Themes:
- High Voltage Engineering, Condition monitoring
- Funding:
- TechImp SPA
This project aims to study and model partial discharge (PD) in a cavity, and induced physical-chemical effects. Among which effects degradation, damage rate, and eventually a life model are the main interests of this project. Different from other PD studies and modelling, this project focuses on detailed physical and chemical phenomenon after each discharge event. Major considerations include the energy spectrum of electron streams impinging into the cavity surface, physical-chemical effects brought on by this process such as polymeric bond breaking, local accumulation of matter, and changes of conductivity. Based on above information, it is hypothesised that damage growth rate can be derived, and a global failure time estimated. During the project, simulation and laboratory studies are carried out simultaneously, aiming at producing comparable and comprehensive result. Simulation studies are based on Matlab and COMSOL modelling, and for laboratory work, insulating materials (XLPE, LDPE, and epoxy) are comprehensively assessed over the life time of the project.
Primary investigators
- Prof. Paul Lewin
- Prof. Alun Vaughen
- Dr. James Pilgrim
Partner
- TechImp SPA
Associated research group
- Electronics and Computer Science
- Date:
- 2012-2016
- Themes:
- High Voltage Engineering, Space and surface charge
With growing interests in renewable energy, high voltage dc transmission has become a hot topic worldwide. Charge accumulation under high voltage dc is a major issue as its presence distorts the electric field, leading to premature failure. In the present project, we aim to chemically treat polymeric insulation and change charge transport characteristics of the material via fluorination process. Various samples will be electrically characterised and tested, so an optimal processing condition can be achieved to meet practical requirements as dc insulating material. Modelling and simulation of electric field distribution with new developed insulating material have been planned to help design an insulation spacer in high voltage dc GIS systems.
Primary investigators
- am306r
- George Chen
Associated research group
- Electrical Power Engineering
- Themes:
- High Voltage Engineering, Space and surface charge, Liquid dielectrics
- Funding:
- National Grid plc
High voltage DC power transmission technology has attracted considerable attention and will play an important role in the UK future transmission system. This project investigates the performance of the oil-paper insulation system used in HVDC transformers under a variety of electric stress conditions. It attempts to determine the effects of oil resistivity and other insulation conditions parameters on the capability of the insulation to withstand the electric stresses seen within HVDC transformers particularly during polarity reversal or other changes in stress. The pulsed electro acoustic (PEA) technique is used to measure the charge accumulation in oil-paper insulation system under different stresses and oil conditions, especially the polarity reversal. Oil conductivity will play an important role in the polarity reversal test of HVDC transformers, therefore, it is important to understand the characteristics of oil under dc conditions. The project intends to measure oil conductivity over a range of electric fields and temperatures. In addition, oil conductivity provides an important diagnostic measure for the insulation of a transformer.
Primary investigator
- Professor George Chen
Secondary investigators
- Miao Hao
- Yuan Zhou
Associated research groups
- Electrical Power Engineering
- Electronics and Electrical Engineering
- Date:
- 2011-
- Themes:
- Space and surface charge, Liquid dielectrics
- Funding:
- Chinese Scholarship Council
This project is concerned with modeling conduction process in liquid dielectrics, specifically where transformer oil is subjected to high electric stress. The physical processes including the generation, recombination and motion of free charge carriers are modeled so that the development of streamers and their respective discharge characteristics in transformer oil can be simulated using a FEA software package. The advantage of this FEA software is its ability to accurately model dynamic, thermal and electrical processes simultaneously. Future work involves validation experiments that will be undertaken at the Tony Davies High Voltage Laboratory. This project is undertaken with collaboration with the State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing University.
Primary investigators
- cj8g11
- Paul Lewin
Associated research group
- Electronics and Electrical Engineering
- Date:
- 2012-
- Theme:
- High Voltage Engineering
- Funding:
- Mars Space Ltd
The aim of the research is to study the factors affecting the lifetime of pulsed plasma thruster (PPT) for nano and pico satellites applications and to optimize their performance whilst keeping lifetime long enough to fulfil their mission requirements. The baseline thruster to be used in the campaign will be the PPTCUP propulsion subsystem already developed at the University of Southampton to provide drag compensation for Cubesats. The test campaign is mainly focus on the performance testing and on the lifetime. The performance testing needs to verify the thruster performance in terms of impulse bit, thrust, specific impulse; a thrust balance able to measure the impulse bit delivered by the PPT will also be developed. The lifetime has the aim to verify the PPT lifetime and its total impulse capability. The test will consist in firing the thruster until all the propellant has been used or until the required total impulse has been reached. The results obtained from the whole test campaign will be used to develop a model able to predict the influence of the thruster geometric design parameters over performances in terms of thrust, specific impulse and ablated mass per shot. The tests will also be used to understand what the main life limiting mechanism of PPTCUP is and how its lifetime can be extended.
Primary investigators
- Steve Gabriel
- Michele Coletti
Associated research group
- Electronics and Electrical Engineering
- Date:
- 2009-2012
- Themes:
- High Voltage Engineering, Condition monitoring, Liquid dielectrics, Solid dielectrics
- Funding:
- Ministry of Higher Education, Malaysia and Universiti Teknikal Malaysia Melaka (Chines Scholarship Council), _other
The aim of the research is to investigate and analyse the full discharge events occurring on the oil-pressboard interface that leads to the flow of leakage current. The leakage current is relatively small and insufficient to trip the protection system of a large transformer. The repetition of this kind of discharges could further degrade the barrier board surface. Experimental work to study the characteristics of this leakage current is required to provide understanding and useful information for condition monitoring programs as well as assist manufacturers in improving their design of inter-phase barrier board arrangements. The research is also developing models that are verified against the experimental data.
Primary investigators
- hz3g09
- Paul Lewin
Secondary investigator
- cj8g11
Associated research group
- Electronics and Computer Science