Joint Research Institute (JRI) in Electronic, Communications and Power Systems (ECPS)

Research Activities Summary Advanced Photonic Communications Systems I Glesk, C Michie, I Andonovic (Strathclyde) A.E Kelly, M Sorel (Glasgow) Plastic Electronics Helena Gleskova (Strathclyde) Nikolaj Gadegaard, Faiz Rahman (Glasgow) Advanced Devices: THz Imaging Douglas J. Paul, David Cumming, Tim Drysdale, Asen Asenov (Glasgow) Deepak Uttamchandani (Strathclyde) Donald MacLaren (Glasgow Physics – SUPA) Lee Cronin, John McGrady (Glasgow Chemistry – WESTChem) Sustainable Energy Research David Infield (Strathclyde) Andy Knox (Glasgow)

Advanced Photonic Communications Systems

Significant leverage of existing device level Good Fit? Internationally leading complementary skills across the communications domain Glasgow Integrated Devices Technologies Strathclyde Systems, Network Management, Applications Natural point of overlap and hence collaboration at the subsystem layer Optical Systems Laboratory; 4 core direct fibre linkage between Royal College (Strathclyde) and Rankine Building (Glasgow) Enables common research Drives existing research forward Increases scope for future research Significant leverage of existing device level and systems expertise

Intergrated Laboratory Strathclyde Glasgow

Passive Optical Networks (PONs) WDM PONs for Avionics Dynamic packet equalisation Adjustable Gain-Clamped SOA High temperature RSOAs Strathclyde network modelling, electronics, systems Glasgow device expertise, novel and integrated devices Amphotonix plc World leading devices, Industry foresight BAe Systems Industry foresight SOA WDM RSOA R P C

OCDMA Research unique field-based optical communication test-bed designed and developed to investigate ultrahigh speed serial data rates transmissions and advanced Optical CDMA systems test-bed connects CIDCOM Optics communication research laboratory at Strathclyde with the Rankine Building at Glasgow University investigated the effects of residual dispersion on transmission channels when used by advanced optical CDMA systems Novel technique was developed to enable control wavelength power redistribution within 2D-OCDMA codes which are based on wavelength hopping (WH) and time spreading (TS) successfully tested in a multi user environment under real life conditions during our field trial experiments the bit error rate measurements showed a 1.5dB improvement in the system performance

OCDMA Test-bed Strathclyde-Glasgow

OCDMA Node at Strathclyde

Synergies with Existing Funded Projects Hypix Micro-LED devices for visible light communications High Power, High Frequency Mode-locked Semiconductor Lasers CMOS driven LED array Measurement of absorber recovery lifetime Additional outputs and access to funding!

Plastic Electronics My name is Helena Gleskova and I am a Senior Lecturer in the Department of Electronic and Electrical Engineering of Strathclyde University. My four collaborators, Catrina Bryce, David Cumming, Nikolaj Gadegaard, and Faiz Rahman, are from the Department of Electronic and Electrical Engineering of Glasgow University. In the next 20 minutes I would like to talk about Plastic Electronics, which is one of the research topics of JRI in Electronic, Communications, and Power Systems. I will tell you about our research backgrounds and summarize our activities to date.

What is Plastic Electronics? Alternate terms: ‘organic electronics’, ‘molecular electronics’ Plastic Logic Philips Polymer Vision Someya, Univ. Tokyo Princeton Univ. Philips e-reader e-paper non-planar surfaces sensors e-textiles VTT, Finland solar cells What is plastic electronics? The alternate terms for plastic electronics are Organic Electronics or Molecular Electronics. Chemistry defines two classes of materials: inorganic and organic. Based on this division, organic materials are used to build these electronic devices. The word molecular is used because by changing the structure of these organic molecules, the chemists have been creating new materials with tailored properties. Here are some examples of plastic electronics. The two on the left, the e-reader and e-paper, may be familiar to many of you. The e-reader or e-paper is an electronic version of a newspaper. It is a black-and-white display that is made on a thin plastic foil substrate. The whole display is very light, thin, and flexible. When information is downloaded on the e-reader it will stray there for many days even when the display is powered off. Both Polymer Vision and Plastic Logic have recently opened a factory to fabricate these products. The first products should appear on the market before the end of this year or early next year. Other examples of plastic electronics are organic light-emitting diodes for displays and lighting, solar cells, and sensors and actuators. In all these examples, the devices are fabricated on a planar substrate that can be easily rolled into a cylinder or a cone. These types of surfaces are called developable surfaces. However, plastic electronics can also be made on non-developable surfaces like sphere. Here is an example from our work at Princeton and it shows a linear array of OLEDs on a dome. The last example is from Philips and it shows an electronic textile. Here they combined LEDs with fabric to create lumalive fabric.

Why Plastic Electronics? Light-weight, flexible, rollable products Large-area processing Variety of devices: transistor circuits, light-emitting displays, solid-state lighting, solar cells, sensors, interfaces with living tissue Inexpensive manufacturing Disposable electronics The fastest growing field in electronics Very high market growth expectations From what I just said, you may start to understand why plastic electronics is so attractive. The combination of plastic foils with thin-film organic devices leads to light-weight, flexible and rollable products while taking advantage of large-area processing. One can make variety of devices. The more traditional ones are the transistor circuits, light-emitting diodes for displays and lighting, solar cells, sensors and actuators, while electronic textiles, stretchable devices, and interfaces with living tissues are enabled by this technology. In addition, these materials generally dislike standard fabrication techniques like photolithograhy and new fabrication techniques like printing are being developed. These printing techniques lead to less expensive manufacturing and when the manufacturing cost becomes low enough, one can introduce disposable electronics. To summarize, plastic electronics is the fastest growing field in electronics with very high market growth expectations.

James Watt Nanofabrication Centre (JWNC) Lithography Metallization Plasma processes Microscopy Next I would like to talk about fabrication. Catrina is an expert in design and fabrication of devices based on III-V semiconductors and she is also responsible for all activities in the James Watt Nanofabrication Center that relate to optoelectronic devices. The infrastructure that the James Watt Nanofabrication Center of Glasgow University offers is essential for our research activities. The center possesses equipment for lithography on a micrometer and nanometer scale, metallization techniques, plasma processing, as well as advanced microscopy.

Plastic Electronics Lab Established at Glasgow and Strathclyde The growth facility I would like to start by introducing myself. My research has been focusing on combining inorganic and organic thin-film devices with plastic foil substrates. The picture on the top shows the first amorphous silicon thin-film transistors fabricated on polyimide. That was 10 years ago. The bottom picture shows amorphous silicon transistors fabricated on clear polyimide at 250C. In 1998, Kapton was the only plastic substrate that had glass transition temperature higher that 250C. We deliberately chose the temperature of 150C because very few other plastic substrates could withstand 150C. The standard amorphous silicon process requires temperatures between 250 and 350C. To make the process compatible with plastic substrates, we developed a process where all layers were grown at or below 150C. All amorphous silicon transistor exhibit instability. When these devices are biased, their turn-on voltage shifts to a higher value, as shown on this graph. On the x-axis is the time for which the device was electrically biased. On the y-axis is the change in the transistor turn-on voltage, called the threshold voltage shift. The graph is on a log-log scale. The turn-on voltage is increasing with time in both devices. The top curve corresponds to these transistors, and the bottom one to these. As you can see, the transistors fabricated at 250C exhibit 5 times slower degradation process. As you can see, it took 8 years to get from here to there. During that time, all major chemical companies worked on developing new high-temperature clear plastic substrates for OLED applications. The measurement laboratory

Plastic Transistors Developing low-voltage organic thin-film transistors with operating voltages below 3V for portable, battery-operated applications Invention disclosure undergoing an internal review at Strathclyde 2 PhD students involved in the transistor development – comprehensive transistor optimization process p-channel transistor parameters obtained to date: p ~ 0.2cm2/V·s, VT ~ 1V, S ~ 50mV/decade, Ioff ~ 10-12 A, Ion/Ioff ~ 106

Conducting Polymers Applied To Cell Impedance Sensing impedance spectroscopy of biological cells provides tool for monitoring cell growth and characteristics using microelectrodes and a larger reference electrode conducting polymers (PEDOT) electrodes instead of metal electrodes PEDOT benefit from the material characteristic of transparency, low cost, biocompatibility, and lower interfacial impedance enhances sensitivity Reference electrode Weakened electrical fields Cell on surface Measuring Regular electrical field Insulation layer

Devices and Setup devices with Au electrodes and PEDOT electrodes in order to compare them devices have three wells Au electrode device PEDOT electrode Device Electronics and connector for device

Results Gold and PEDOT comparison Cell growth experiment on PEDOT Gold electrodes show very large impedance at lower frequencies compared to the PEDOT electrodes Impedance of the gold electrode reduces the sensitivity of cell impedance measurement and increases influence of noise. Cell growth experiment on PEDOT cells growing on the surface at three different frequencies over 3 days changes at lower frequencies is most prominent. As cells spread and divide they will gradually cover more of the measuring electrode resulting in an increase in the impedance.

Advanced Devices

Nano-Electronics@Glasgow Silicon Nano-Electronics@Glasgow Si/SiGe resonant tunneling diodes (EPSRC £861k) Ge/SiGe THz quantum cascade lasers (EPSRC £1.7M) Single molecule spectroscopy / sensing and SOI based single electron transistors (EPSRC £3.61M) SiGe thermo-electrics: generators and Peltier coolers (EC ICT FET €2.2M) Si nanowire sensors (industrial funded) Si photonics: sources, waveguides, cavities, detectors, filters, modulators, etc. (industrial funded)

Research Progress 20mW 2.8 THz GaAs QCLs now operating THz polarisation insensitive absorber published THz surface plasmon resonance array detectors published Imprinted THz artificial dielectric quarter wave plate published THz dual band resonators on Si published SiGe THz QCLs designs completed – awaiting wafer growth at Warwick University (EPSRC project) 30 nm Si/SiGe RTDs demonstrated and published SiGe RTD non-volatile memory published 10nm Si nanowire sensors developed

Si/SiGe Resonant Tunneling Diodes Scaling RTDs down to 30 nm

Si RTD Non-Volatile Memory Fast, low power SRAM for CMOS

Silicon Nano-wire Sensor Developments >10nm Aim: breath analysis for mobile phones

Spectroscopy of Single Molecules Using metal gaps to electrically measure HOME and LUMO on POM molecules

Sustainable Energy

Sustainable Energy Growth Binding European targets of Renewable Energy (20% of all EU energy from RE sources by 2020) place specific demands on sustainable energy in the UK15% of UK energy from RE sources by 2020 This requires approximately 35% of electricity from RE Scottish target for electricity from RE is over 30% by 2011 and 50% by 2020 Scotland has Europe’s largest onshore wind farm with 322MW at Whitelee near Glasgow From what I just said, you may start to understand why plastic electronics is so attractive. The combination of plastic foils with thin-film organic devices leads to light-weight, flexible and rollable products while taking advantage of large-area processing. One can make variety of devices. The more traditional ones are the transistor circuits, light-emitting diodes for displays and lighting, solar cells, sensors and actuators, while electronic textiles, stretchable devices, and interfaces with living tissues are enabled by this technology. In addition, these materials generally dislike standard fabrication techniques like photolithograhy and new fabrication techniques like printing are being developed. These printing techniques lead to less expensive manufacturing and when the manufacturing cost becomes low enough, one can introduce disposable electronics. To summarize, plastic electronics is the fastest growing field in electronics with very high market growth expectations.

Facilities outdoor PV test facility laboratory for micro-generation and demand side management test facility for power electronic grid interfaces laboratory for distributed generation and storage finite element simulation and analysis tools

Research Progress Two ETI Phase 1 wind projects (NOVA and Helm Wind) completed ETI project FLOW on condition monitoring for offshore wind continues to make progress and has funded additional PhD student Successful EPSRC SuperGen Energy Networks Hub and Grand Challenge bids Kick off of STAPP EPSRC UK-India project Research visitor from NCEPU, Beijing , May 2010- June 2011 (successful work on SCADA data analysis for wind power) Successful EPSRC bid (to be announced) for IDC in Offshore Renewables