FP6 Project results
A key initiative of the Sixth Framework Programme (FP6) was the development of organic and large area electronics. Within this Programme, the European Commission allocated to this field an overall budget exceeding 100 M€, distributed through specific programmes such as Information Society Technologies (IST), Nanosciences, Nanotechnologies, Materials and new Production Technologies (NMP) and Sustainable development, global change and ecosystems (SUSTDEV). The results of three of these EU-funded projects, namely CONTACT, ROLLED and FlexiDis, are presented in this first issue of the OLAE Newsletter.
CONTACT: Contact printing of electronics and opto-electronics
In response to the EU initiative in organic electronics, in July 2004 the CONTACT consortium was formed and began a project to develop processes for the gravure printing of organic thin film transistors (TFTs).
In order to achieve, support and demonstrate the outcome of this objective the following developments and activities were started:
- The formulation and optimisation of the three inks required to form the organic thin film transistors, i.e. gate, gate insulator and gate electrode. These inks are required to be a semiconductor, an insulator and a low resistance conductor respectively.
- A novel high precision benchtop gravure printer capable of printing 25 micron features with a positional accuracy of 10 microns, known as the Labratester II.
- Display demonstrators based on the outputs of items 2 and 3.
- Novel glass clichés that would allow a relatively easy route to the optimisation of the structure of the cells that transfer the ink to the substrate during the gravure printing process, thereby leading to good control of film thickness and uniformity.
- Project Management
The final CONTACT consortium consisted of 7 partners, namely Imperial College (1), Merck Chemicals (1), Norbert Schlaefli Machines (2), Technical University of Ilmenau (4), IMEC (1), Asulab (3) and Imperial Consultants (5). The main area of activity of each partner is shown in brackets. The project was truly collaborative in that all partners were involved in two or more aspects of the project. For example, Asulab assisted with the design of the novel gravure printer and Schlaefli contributed to the development of the glass clichés.
As in any highly ambitious project not all targets were satisfactorily achieved, but one of the main objectives, namely item 1, was not only achieved but taken to the next stage and improved in order to be compatible with the first process used to fabricate the liquid crystal display (LCD) that would be addressed by the gravure printed array of organic thin film transistors. After successfully developing a process for the fabrication of organic thin film transistors based on gravure printing, it was found that the first step of the process used to fabricate the LCD dissolved the gate insulator material. Consequently, a new gate insulator material was developed which proved to be stable. Using this material and other gravure printed layers led to the fabrication of a small number of organic thin film transistors that had state of the art operating characteristics.
Another successful outcome of the project was the development of glass clichés. This novel approach enables the gravure printing of high resolution patterns of conductive inks that could be used for the gate electrode and films of the gate semiconductor having the required thickness of ~100 nm and good thickness uniformity.
An aspect of the project that proved to be not achievable with the available resources was the fabrication of the Labratester II, the novel high precision benchtop gravure printer, which in turn prevented the fabrication of the main demonstration display, an organic TFT addressed twisted nematic LCD. However, Asulab were able to demonstrate a reflective full colour LCD that had been fabricated using mainly printing processes.
Another positive feature is that Schlaefli has continued the development of the Labratester II, which was shown at an exhibition at the beginning of June 2008. In addition, once completed the Labratester II will be transferred to Asulab, who are prepared to work with Schlaefli on the commissioning and further optimisation of this equipment.
Overall, CONTACT was successful in developing materials and inks that can be used for the gravure printing of organic TFTs, novel glass clichés and for initiating the development of the Labratester II. All of these activities will contribute to the European development of organic electronics which are expected to be the next "big thing" in the world of technology.
FlexiDis: Flexible Displays
FlexiDis aimed to research the main technological issues for flexible displays. The demonstrators realized in FlexiDis included two different display technologies, namely full-color organic light-emitting displays (OLEDs), and e-paper monochrome electrophoretic displays on rollable plastic substrates.
In this way, use for the automotive industry, mobile telecommunications, and sportswear was examined. At the end of its runtime, FlexiDis has achieved the following results:
- The first production-ready flexible display manufacturing method compatible with existing facilities was developed, and now runs in the Thales LCD fab;
- PolymerVision, a spin-off company, was created with a focus on rollable e-paper organic TFT displays;
- PolymerVision will release its UK manufactured Readius in 2008;
- Plastic Logic contributed to the project and is now also setting up the manufacturing of e-paper displays in Germany;
- The first flexible OLED on plastic with an active-matrix backplane was introduced, etc.
Overall, the Integrated Project (IP) FlexiDis has contributed to increase innovation and competitiveness of the European industry in flexible displays and to Europe's recognition as a world leader in this field.
ROLLED: Roll-to-roll manufacturing technology for flexible OLED devices and arbitrary size and shape displays
ROLLED, "Roll-to-roll manufacturing technology for flexible OLED devices and arbitrary size and shape displays", is a R&D project funded by the IST program of the European Commission's 6th Framework Programme (FP6-2003-IST-2-004315). The ROLLED project started 1.8.2004 and will end 31.7.2008. The project is coordinated by the Technical Research Centre of Finland (VTT). The other partners of the ROLLED consortium are CSEM (Switzerland), INM (Germany), UPM (Finland), Hansaprint (Finland), Ciba (Switzerland) and PolyIC (Germany).
ROLLED’s goal is the development of a cost-effective, volume-scale, roll-to-roll manufacturing technology for the realization of flexible OLED devices with arbitrary size and shape pixels on web. These technologies are developed in order to achieve a good understanding of the production process flow. On the contrary to typical semiconductor light sources, OLEDs have the potential to be processed in continuous roll-to-roll processes.
This requires selection and modification of suitable materials, effective patterning technologies, development of the manufacturing processes and improved encapsulation technologies. The ROLLED consortium has developed a transparent roll-to-roll produced barrier foil in lab scale with the water and oxygen transmission rates below 0.005 g×m-2day-1. Currently, the consortium is transferring the technology to pilot scale production.
In addition, transparent conducting ITO patterns have been gravure printed on flexible foil achieving the sheet resistance ≤500 Ω/sq and transmittance >88%.
The main achievement of the project so far are roll-to-roll manufactured OLED demonstrators where 5 different layers, including Aluminium cathode, have been printed on flexible barrier foil.
The device performance is in the same level as that of the devices with evaporated Al cathodes. The consortium is also developing low work function metal inks for cathode, to improve the performance of the printed device further. Currently, the consortium is working on the final demonstrator, which will be ready at the end of June 2008. The demonstrator will be a pilot line printed two colour device consisting of nine printed layers.