Organics

Aerosol Jet System will be used for the development of Organic Thin Film Transistors

Following on from the shakeout in OLED developers, IDTechEx sees the same thing happening now in Organic FETs.

NPL, offers Printed Electronics World readers to participate in a short on-line survey, where you will be able to give your opinions on the priority areas for organic and plastic electronics.

Dr Harry Zervos, IDTechEx reports on the highlights of the second International Summit on OPV Stability held on April 21-22, 2009 in Amsterdam.

Holst Centre - founded by the Belgian nanoelectronics research center IMEC and the Dutch research center TNO presented a 128 bit organic RFID transponder chip with Manchester encoding and anti-collision protocol.

Physicists at Umeå University in Sweden have now developed a new and simple method for producing cheap electronic components.

Optomec's Aerosol Jet system has been used to fully print Carbon NanoTube (CNT) based Thin Film Transistors (TFT) with operating frequencies over 5 Gigahertz (GHz). The work was conducted in collaboration with the University of Massachusetts and Brewer Science, Inc.

A new organic high-performance dye-sensitized solar cell (DSSC) has been developed that does not use Ruthenium.

Polyera and BASF Future Business GmbH have invented a novel n-type organic polymer semiconductor with high mobilities (greater than 0.5) and robust processability.

"If organic photovoltaics - to take just one example - are ever to be realized and marketed, we need to understand how the film formation process works,"

The news media are full of the details of the global financial meltdown. Is this affecting finance for the small companies and start-ups involved in printed and potentially printed electronics and electrics? We think not.

The German government is investing EUR 2.5 million in a project that will significantly increase the lifespan of organic solar cells (OSC) with the goal of yielding competitive organic photovoltaics (OPV) for potential commercial use.

IDTechEx finalises its report on the Intellipak conference held on 5 November in Sweden

IDTechEx report on the Intellipak conference held in Sweden on 5 November that was mainly in Swedish and partly in English with just over 40 attending and excellent content.

A team of chemists at The Johns Hopkins University has created water-soluble electronic materials that spontaneously assemble themselves into "wires" 10,000 times smaller than a human hair.

IDTechEx technology analyst Dr Harry Zervos attended the meeting of the Society for Information Displays in London, where the latest research and development efforts were discussed and presented. Some of the presentations are described below: In his plenary address, Dr Dago de Leeuw from Philips- TU Eindhoven spoke about "Polymeric non-volatile memories" Philips introduced the first ever 13.56 MHz first RFID system based on organic transponders (IEEE, J Sol. St. Circuits, 2007) and Poly-IC were the first to produce such RFID tags in a roll-2-roll process. The next step would be the ability to include programmable memory to store data, with requirements such as: Resistive/rewritable Reproducible Reliable Program cycle endurance Retention Fast switch times - Resistive switching Switching observed on electron only PLED devices with aluminum electrodes, but with very low yield. Yet, yield improved with UV/O3 treatment. That's unexpected as the addition of a 50 nm alumina layer- an insulator (!)- increased yield. The forming of the memory was attributed to "soft breakdown" of Al2O3. The type of polymer used was found to be irrelevant, as was the type of electrode and type of oxide irrelevant. In the process of the soft breakdown in the oxide, the polymer acts as nothing more than a current-limiting series resistance. Dr DE Leeuw finished his talk with the message to remember: "Let's store data by oxidizing the electrode before processing!" Prof Jenny Nelson of Imperial College London spoke on the "Modeling of charge transport in disordered organic semiconductors". Taking into account the fact that chemical structure, side chain length and processing/ macroscopic parameters (e.g. temperature, electric field) influence mobility, simulations showed that ordered/crystalline-regions increased with temperature. As the surface roughness affects simulated mobility, better behavior was observed when processing at higher temperatures. The strong influence of molecular packing was also highlighted but was found difficult to compute and verify. In his talk on the charge balance in organic light emitting devices, professor Franky So of the University of Florida pointed out that charge balance is important to achieve high efficiency devices, whether small molecule or polymer. The bottleneck here is electron transport, the high triplet energy and high electron mobility needed while avoiding triplet exciton quenching to enhance efficiency. Prof Donal Bradley gave an overview on Molecular Electronic Materials and Devices. He focused on the following points: - Electrode materials for cathodes: low work function suited to efficient injection. Encapsulation-permeability an issue for plastic substrates. - Some of the oxides used as anodes can also be used as electron injection layers. Nanostructured TiO2 studied to this effect, du eto its use in DSSC solar cells. In order to change its performance a layer of MoO3 was inserted which unfortunately had a detrimental effect to the device. Replacing titania with zirconia achieved a better performing device - Vapor Phase Polymerized PEDOT: VPP PEDOT: Good work function for hole injection, makes up for ITO's shortcoming in that respect. Efforts are being made to optimize VPP PEDOT for OLEDs. Added PEDOT:PSS leads to enhanced hole injection and much improved efficiency. There are hopes to be able to use VPP PEDOT instead of ITO, when using an additional PEDOT PSS layer. A discrete component demonstrator of OLEDs and OPDs has also been fabricated. According to Dr Madec of the University of Manchester, who are looking into the possibility of inkjet printing of organic TFTs, small molecules are best for TFTs due to better packing. The group studied different formulations of TIPS pentacene; a soluble derivative of pentacene. The research proposes formulations of inks and use of different types of binders in order to achieve rheological properties that would be making the ink compatible with Inkjet printing and look into the links between morphology and mobility. There was also a presentation from Dr Xiaojun Guo from Plastic Logic on the deay of the oepnign ceremony of the company's production facility in Dresden. PL has received over US$200 million in global investment and have now demonstrated an e-paper flexible display,10-14'' in size, 25-50g in weight with the overall product weighing less than a pound , thin at a ¼ inch, robust, flexible and conformal with low power consumption. The company uses solution processable polymer semiconductors and dielectrics, compatible with low cost PET substrates with a scalable manufacturing route based on direct writing and laser patterning technologies. Active matrix driving scans each line quickly, approximately 20ms per frame. Passive matrix driving would take several minutes to update the display so each pixel uses a TFT for driving and a capacitor for data storage. Backplane requirements: - TFT with low on resistance, low source/gate line resistance - TFT with high off resistance, - high yield and uniform performance - stable performance for constant product use The stability of the device was tested through electrical stressing. No change in device performance was recorded after 250 hours of electrical stress, (.8s ON, .8 s OFF, performance measured every 5.5 hours).

In collaboration with Silvaco Data Systems, CDT has developed a model to design and simulate circuits using OTFT (organic thin film transistor) technology.

Researchers from the National Institute of Standards and Technology (NIST) and Seoul National University (SNU) have learned how to tweak a new class of polymer-based semiconductors to better control the location and alignment of the components of the blend.

This week, the German ministry for Education and Research BMBF announced the 5 winners in a strategic program which aims to strengthen cooperation between science, research and industry with 200 million Euros over the next 5 years.

In Portugal, a new field effect transistor with paper interstrate layer has now been developed.

Printed electronics today is mainly a matter of inorganic rather than organic chemistry and the next ten years are unlikely to see the inorganic part drop below 50% of the high value materials required.

Printed electronics holds possibilities for applications including printed organic solar cells, radio frequency identification (RFID) tags and flexible displays

Over the last three years significant developments have been made with efficiency of organic based PV cells.

Gate dielectrics in printed electronics can make the transistors exhibit higher current and lower voltage and are a hot area of research.

Germany's expertise in industrial production, printing processes, and chemicals - all essential elements to printed electronics - make it a leading location for investments.

OTTI, the East-Bavarian Technology Transfer Institute, will host an experts' forum on printed electronics 3-4 March in Regensburg, Germany.

Only RFID offers the electronic printing industry the potential of ten trillion devices yearly, in this case replacing barcodes.

Organic materials are of great interest for electronics applications, as they have many advantages over their inorganic counterparts.

Using room-temperature processing, researchers at the Georgia Institute of Technology have fabricated high-performance field effect transistors with thin films of Carbon 60, also known as fullerene.

This two day meeting was organised by the Organic Materials Innovation Centre (OMIC) and the UK Displays & Lighting KTN and focused on research activities that address the major challenges in the chemistry, processing and physics of organic transistors, sensors, OLEDS and photovoltaic devices.

We are increasingly seeing demonstrations, samples and first products of printed electronic transistors and other products. Companies are focusing on yield improvements and a necessary part of this is adequate inspection of devices, preferably at high speed.

By laser-treating ink consisting of coated nano-particles of metal, scientists in Switzerland are able to manufacture a wide variety of printed microelectronics.

Transistors are the engine of the new electronics just as the silicon chip is the engine of the traditional electronics.

Products like the flexible transistor will account for 10 percent of the information technology (IT) device market within the next 10 years say researchers at KIST.

Procurement of equipment is already underway for printing conductive inks, metallised circuits and novel barrier layers onto flexible substrates and further R&D programmes for new customers will be introduced in the coming months.

Stretchability is needed in electronics if it is to be foldable, tightly conformal or following the form of something that changes in shape, like the human body.

Scientists at the Weizmann Institute of Science, Israel together with colleagues from the U.S.A., recently succeeded in being the first to implement doping in the field of molecular electronics - the development of electronic components made of single layers of organic (carbon-based) molecules.

Two and a half years after its start, the European research project OLLA* presents its second milestone: a prototype white Organic Light-Emitting Diode (OLED) light source, with an efficacy of 25 lumen per watt and a lifetime of over 5.000 hours

Brussels Belgium 28 Feb 1 March