OLED lights the way

OLED has been grabbing the headlines in the consumer display market for a few months now, but professionally speaking it’s been more of a slow burn. Steve Montgomery reports on the up-take for displays, and also looks at other applications of the technology.

Despite the fact that Organic Light Emitting Diode (OLED) panels have been available for several years and millions of dollars have been invested in research and development, the commercial release of displays using this technology appears to have stalled.
Currently OLED panels are used widely in mobile phones, MP3 players, cameras and games consoles, but only at small sizes; up to 3-4” diagonal and in some devices such as picture frames up to 7”. The largest freely available OLED TV is only 11” with a hefty price tag. iSuppli, a market research organisation estimates that the market size of OLED panels has grown to more than half a billion dollars annually.
Vinita Jakhanwal, principal analyst, small/medium displays, for iSuppli, says this situation will change: “Global revenue from shipments of OLED panels for use in televisions will surge to $1.8 billion in 2015, up from $10 million in 2009. This will make television the biggest revenue-generating application for OLED panels in 2015, surpassing the much higher-volume market of main displays for mobile phones.  The large sizes of televisions relative to the small displays on mobile phones means the pricing for their OLED displays is dramatically higher, boosting revenue.”
Current manufacturing challenges and limited production mean that costs of the larger panels are much higher in relative terms than standard LCD panels. Jakhanwal continues: “The average price for an 11-inch OLED television is presently about $2,500, compared to $704 for a 42- to 44-inch LCD television. OLED TVs will remain small in size and high in price in the coming years, consigning them to a small niche of the global television market at least through 2015.  There are few suppliers which precludes competition that could drive prices down and volume up.”
Among the features that make OLED attractive are the advantages offered by OLED technology as compared with LCDs. Aside from image quality, OLEDs have a slim form factor and consume much less power than LCDs, which makes them attractive to environmentally conscious consumers.
However several barriers to OLED adoption remain, including low manufacturing yield, technological and quality challenges.  There is currently no investment in fabrication plants capable of producing larger OLED panels that could compete directly with the most popular LCD TV sizes. Because of this, it is unknown whether high-volume manufacturing of large-sized OLED panels can generate yields that are competitive with other display technologies.  
The displays also suffer from burn-in; a phenomenon that leaves an artefact on a screen after a static image is displayed too long, which was present in early plasma screens but has since been solved. The increasing competitiveness of LCDs is a factor, as they are improving their refresh rates, moving from 120 Hz to 180 Hz and 240 Hz. They also are using LED backlights to improve colour performance; getting thinner, which undermines an OLED advantage. Finally TFT-LCD prices are dropping.
High cost and limited market demand has led to withdrawal of Sony’s 11” TV set from the Japanese market, although it is still to be available in North America and Europe. NEC Display Solutions, another large player in the flat panel market is also very aware of the market potential but reluctant to commit, Clemens von Braunmühl, product manager monitors: “OLED is a very good alternative to conventional LCD technology, but at the present time it is not of interest to our customers. We would prefer to wait to see how OLED develops and also whether this technology meets our high demands when it is ready for the market.
“OLED technology has a great potential for office and desktop applications, we are convinced of that, but it will be some time until OLED panels can be manufactured cost-efficiently and can hold their own with LCD technology. As soon as the total cost of ownership with regard to power consumption and lifetime shifts in favour of OLED, we will of course also offer our customers OLED monitors."  
Despite manufacturing issues, many companies are continuing to demonstrate large screen displays in an attempt to seed the market. Visitors to CES this year were treated to a number of prototype displays, including a 24.5” OLED from Sony, 15” from LG and a 3D set from Samsung. Beyond these presentations, none of the companies have declared definite strategies or product announcements. In Samsung’s case, according to Nadia Szajkowski: “For Samsung’s display portfolio, the key technology for 2010 is the use of LED across all categories in the range. For example we recently announced our first LED data projector, as well as LED large format displays. Although OLED is present in our portfolio contained in other devices such as digital photo frames and mobile handsets, we currently do not plan to scale up the technology within display in the immediate future. “
One manufacturer that has made commitments is Mitsubishi Electric, with the announcement of a scalable modular display.  According to Peter van Dijk, business manager: “Mitsubishi Electric has been developing OLED technology for several years but has only just recently revealed the fruits of that research to the public. We have always seen OLED very much as an out of home display technology as it has several features that make it uniquely suitable for this kind of application. Mitsubishi has pursued a somewhat different technology path than other manufacturers in that it has always been our intention to produce a robust, large-screen display technology that can be mass produced.
”Our technology is based on a simple passive design, rather than the complex and expensive active OLEDs being employed in flat screen TVs.  In its current form, our OLED delivers a brightness of 1200 cd/m² - roughly 3 times brighter than LCD.  Final production models will produce 1500 cd/m² which is as bright as some LED screens.
“Comparing the Mitsubishi OLED technology to LCD, OLED is much brighter and because it is a light-emissive technology it exhibits extremely good black level performance and at 3mm pixel pitch it offers very good viewing distances but at greatly reduced cost to a similar pitch LED screen.  OLED modules can be made extremely thin; screens can be made light enough to install on virtually any flat surface, and because the Mitsubishi system is modular, we are not limited by size or shape – we can even create curved screens.
“We showed an advanced prototype 149” OLED screen at ISE this year but thanks to our unique scalable design, we are now able to produce OLED screens of virtually any size.  Commercial OLED display products based on this technology will be announced soon.”
In the AV world, we tend to view OLED as just a new technology for displays, however as Gildas Sorin, CEO of OLED materials and technology manufacturer Novaled points out: “In the world of electronics Organic Electronics (OE) lies  before us.  OE can be described as electronics and photonics products created with the use of organic materials.  These materials may be semi-conductive, light-emitting or photo active. OLED display and OLED lighting are two examples of the use of OE constituents but beyond these there is a multitude of other applications under development, from solar cells to RFID.
“The OE move is comparable to the silicon move in the late 1970s. But contrary to the silicon world, requesting heavy industrial investments, organic semiconductors can be produced via printing technology and cheap vacuum deposition methods. The market expectations show a rapid growth in the coming years to reach a value above US$ 34 billion by 2014.”
Whilst OLED display development is struggling, OLED lighting appears to be undergoing a rapid and successful development strategy. A recent report by DisplaySearch indicates that “The OLED lighting market is setting the stage to take off in 2011, with OLED lighting revenues forecasted to surpass displays in the 2013/2014 timeframe, reaching $6 billion by 2018.” 
According to Dr. Jennifer Colegrove, director of display technologies: “Hundreds of millions of dollars have been invested in OLED lighting, especially in Europe, the US, and Japan. Although OLED displays have been in mass production for about a decade, OLED lighting has just started sampling and small volume production. This is due to the fact that OLED displays and OLED lighting face different challenge.”
Major lighting manufacturers have already released commercial products. Osram’s ORBEOS is a round lamp with a surface area of 80mm and a thickness of just 2.1mm.  “OLEDs open up totally new design possibilities for architects, lighting planners and designers – it is possible to create illuminated areas with them such as lit ceilings or partitions,” says Markus Klein, senior director SSL at OSRAM Opto Semiconductors.
“ORBEOS adds to the wide range of lighting in the premium segment. With enormous technical advantages in energy savings; it delivers 1,000cd/m² with power input of less than a watt, and has a completely new, highly attractive appearance.” Giant lighting manufacturer, Philips Lighting offers Lumiblade OLED lamps. “The OLED technology is available to create large diffuse light sources of any shape, but the opportunities they present go much further than lamps,” says Kristin Knappstein, Business development Manager at Philips Lighting.
“OLEDs are actually a kind of building block – a new type of magic material – that can be combined with others to produce a striking new and creative whole, such as clothing, furniture, vehicles, jewellery, works of art and architecture.  Transparent OLED panels will be able to function as ordinary windows during the day, and light up after dark, either mimicking natural light, or providing attractive interior lighting. During the day, they could also function as privacy shields in homes or offices. The possibilities are endless.”
We have seen several false starts and promises of new OLED displays that will transform the market over the past two or three years; each one fading away as manufacturers change or shelve plans or as in Sony’s case withdraw products from market. This is largely because technical problems in manufacture and reliability have not yet been overcome. The market for flat panel displays is driven by consumer demand.
Perhaps the demand for OLED panels is not sufficient to drive manufacturers on to solve the technical problems as consumers already have sufficient choice of CFL and LED backlight technologies to choose from. However newer demands from the lighting industry could generate much higher quantities and open up a market for a technology and create a pull-through effect that will provide these solutions.  If so, we could yet see larger OLED panels in general manufacture over the next couple of years for use in video and computer displays.

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