The Printable Electronics Technology Centre (PETEC) is the UK's major new design, development, and prototyping centre for the commercialisation of printed electronics. With 180 present, the launch included keynote lectures from international experts in the field of printable electronics. Speakers gave their views on the opportunities, applications, markets and future for this emerging technology, on the theme 'from innovation to commercialisation'. In addition, there was a small exhibition demonstrating the thought-provoking scope and applications for printable electronics, from prototypes to artworks, and the opportunity to see first hand what PETEC offers businesses of all sizes. Introducing the event, director Dr Tom Taylor said that the priority is organic electronics in the form of flexible OLED lighting and electrophoretic displays with their drive transistors and organic photovoltaics. This provides a route to market for the formidable UK academic base in organic electronics. It is a bold step to meet some of the most impressive mainstream competition in printed electronics head on in three challenging sub-sectors where many technical problems remain, including lifetime and operational parameters.
Lord Alec Broers, former Vice Chancellor of Cambridge University gave the opening presentation and later formally opened the facility. He is a renowned researcher from the age of the silicon chip and he made it clear that he sees printed electronics as the new dawn. He is Chairman of the House of Lords Science and Technology Select Committee and he was highly critical of what he saw as the poor and fitful support of industry provided by successive governments. He said he still had a letter sent to him by a minister in reply to his letter to a prime minister. This contained the words, "It is not the job of Government to support British industry". However, he praised the government - industry collaboration that led to the establishment of PETEC. IDTechEx noted that there were a large number of people in the audience from Germany where the level of support and consistency of purpose in supporting industry is of an altogether different order.
Professor Henning Sirringhaus, the Hitachi Professor of Electron Device Physics at the Cavendish Laboratory, University of Cambridge then gave a presentation on the technology. He is also a co-founder and Chief Scientist of Plastic Logic Ltd., a technology start-up company commercialising printed organic transistor and flexible display technology for applications in electronic readers. It was a salutary lesson for the British that Plastic Logic of Cambridge UK set up its production in Dresden not the UK, because the financial incentives were far superior as was the local infrastructure. The Cavendish Laboratory is one of the three top research centres in the world in organic electronics: it was there that light emitting polymers were discovered. He pointed out that, although most of the operational parameters of printed organic transistors and photovoltaics are inferior to those of printed silicon nanoparticles or printed zinc oxide based semiconductors, there are some unique advantages even on the operational front. It is not just a matter of being potentially very low in cost, lightest weight and thinnest. He cited ambipolar conduction (electrons and holes) combined with light emission, this creating the possibility of light emitting transistors replacing OLED displays with separate OTFT backplanes one day.
Henning described the new Cambridge Integrated Technical Centre backed by Merck, Plastic Logic and others, that will facilitate the commercialisation of future inventions in printed electronics in an integrated fashion. This is upstream of PETEC and complementary in nature. He is on the board of a spin off that will make organic printed photovoltaics for outdoor use using £5 million funding from the Carbon Trust. He told us that the challenges include life, efficiency and weathering of the polyester film. Dr Tom Taylor, director of PETEC told us that the latter problem may be the easiest to overcome because a coating can do it. Henning seeks to beat the economics of conventional silicon PV and he perceives that considerable efficiency improvements are necessary to achieve this. He said that Plastic Logic is responding to the need for flexible e-books with product in the shops in the first quarter of 2010, initial capacity being hundreds of thousands of units yearly. He mentioned the new n type printable organic semiconductors, saying they now approach the mobilities of the best p type ones. He thinks there is scope for further improvements in mobility of organic semiconductors in general.
Dr. Vivek Subramanian spoke next. He co-founded Matrix Semiconductor, Inc., in 1998. Since 2000, he has been at the Department of Electrical Engineering and Computer Sciences at the University of California, Berkeley, where he is currently an Associate Professor. His team works on a remarkable variety of printed organic and inorganic options. He described the pros and cons of ink jet and gravure - both of which he uses and his work on zinc oxide based transistors which are 0.2 to 10 microns thick and are transparent whereas alternatives are not.
He focussed on RFID and sensors in his talk, concluding that "RFID is really a price play" whereas sensors are not and they are therefore a more promising application of organics. Printed RFID will be used for anti-counterfeiting, stock control, anti-theft and other functions, he said. One opportunity exciting retailers is the possibility of encouraging supermarket shoppers to take the goods nearest expiry by giving them price incentives, something not practicable with manually changed pricing. It might be done by radio controlled pricing on the product itself with printed displays on printed RFID or by similar shelf edge labelling. The plus of printed electronics was seen as not cost per se but cost per unit area being reduced by at least a factor of ten.
He is on the Board of nearby Kovio which prints nanosilicon transistors with nanosilicon inks getting mobilities of hundreds of cm2/vs and meeting RFID standards written around silicon chips. For example, current performance with 300 micron ink jetted features is 96 bits HF with approaching 5000 transistors at 106kbps, suitable for ticketing and other applications at what is the world's favourite RFID frequency. He is a visiting professor at Suncheon University in Korea where he is impressed by their use of a regular printing machine to make carbon nanotube transistor circuits. However, he sees a place for the more primitive organic and compound inorganic printed RFID, not least because nanosilicon calls for a stainless steel substrate. He concluded that standards must be specially written for them. Printed options consume more power and have shorter range.
Professor Jin Jang gave a summary of Korean research in organic electronics where the audience noted the profusion of long term commitments to funding, such as the 2002-2011 "Frontier Project" and the seven year "Next Generation New Technology" funding for printed oxide semiconductors etc. but also the modest amounts involved. He is Professor at the Department of Information Display, Kyung Hee University and also Director of the Advanced Display Research Centre which engages with the semiconductor industry in Korea, setting up co-operations to support industrial leaders in developing new generation inorganic and organic semiconductors, and printable electronics.
Much of the organic work is on small molecule semiconductors and it has progressed from pentacene, which cannot be printed directly to TIPS pentacene that can, achieving over 1 cm2/vs, ahead of commonly printed polymeric semiconductors. He sees all organic semiconductors as being as stable as amorphous silicon in the transistors so commonly seen in display backplanes. Polythiophenes such as P3HT are seen as among the best. The backplane of the printed displays that are being researched consists of p type transistors, the operational limit of 1-10Hz being no problem in the e-book type of application. LCD displays were the first to be driven with OTFTs. Top and bottom gate horizontal architecture is of interest.
In printed photovoltaics, he mentioned the huge number of researchers in Korea pursuing OPV but also the teams at Dongjin Semichem and the Heeger Laboratory at KIST working on Dye Sensitised Solar Cells DSSC. These technologies have potential uses in energy harvesting for small devices, not just for generating grid electricity. ITO free OPV has been demonstrated.
We learned of the formidable display value chain in Korea with 600 local suppliers to four very large display manufacturers. He is encouraged by a forecast of $12 billion world market for flexible displays in 2017 made by local market researchers DisplayBank. That compares with a $40 billion LCD market today.
Ted Tohma then covered the situation in Japan, emphasising the activities of the very large display industry there. He is a world recognised expert in OLED and for championing OLED in Japan. Ted Tohma was previously MD at Pioneer OLED and responsible for setting up the first OLED manufacturing line in Japan. He noted that small molecule OLEDs have 5-7 layers whereas PLEDs are simpler. He strongly advocated chasing performance first rather than cost and in his view that meant developing printable phosphorescent (exciton triplet) OLEDs with improved blue and lifetime and extension to large flexible substrates.
He also covered OLED lighting giving the view that it is better than incandescent at 10-30 lumens per watt but it must gain a clear lead on Compact Fluorescent at 30-60 lumens per watt and even traditional fluorescent at 60-100 lumens per watt.
Wolfgang Mildner, Chairman of The Organic Electronics Association (OE-A) and Managing Director of PolyIC GmbH & Co.KG in Fürth, Germany described how the O&EA has had its biggest increase in membership in the last six months. This is further evidence of growth in interest in printed electronics. Indeed, IDTechEx is seeing growth in its Dresden Printed Electronics event for April, even following the record growth the year before.
There was a tour of the facility which will have many forms of printing and supportive activity. Already there is low temperature RF sputtering and two types of ink jet equipment installed and an Optomec acoustic jet printer on order. Other equipment is working in a sister facility and it will be shipped in shortly. In house start up PolyPhotonics now has considerable funding to commence work on commercialising OLED lighting. DuPont-Teijin films, global leader in PET and PEN substrates for printed electronics is nearby as are supportive local universities so here we have an admirable centre of excellence in printed electronics with sensible funding and a very promising future as a world class force in the subject.
Top Image: Printed electronics. (Source: Computer Finance)
For more attend: Energy Harvesting and Storage Europe 2009