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Why You Should Learn to Spell OLEDs

April 1, 2012
Ready for another revolutionary lighting technology? OLEDs offer some exciting potential, but they are still miles from the market.

Just when you were getting comfortable with the fact that you might someday actually sell light-emitting diodes (LEDs) for general-lighting purposes other than exit signs, there's another new lighting technology over the next hill that one day could give LEDs and all other types of a lamps a real run for their money.

OLEDs, or organic light-emitting diodes, have been around a while as the display screens on cellphones, televisions, computers and other electronic devices, where they have established themselves as a super-thin alternative to LED and plasma screens.

The web-site, www.oled-info.com, a great resource for both OLED newbies and enthusiasts, says OLEDs work by utilizing “a flat light-emitting technology, made by placing a series of organic thin films between two conductors. When electrical current is applied, a bright light is emitted. OLEDs can be used to make displays and lighting. Because OLEDs emit light they do not require a backlight and so are thinner and more efficient than LCD displays (which do require a white backlight).”

This technical definition of how OLEDs work doesn't do them justice, because their potential applications are limited only by the imagination of lighting designers and architects. In OLEDs we have an entirely new lighting source thinner than the height of two paper clips stacked on top of each other. Like LEDs, they generate light by using semiconductors and stimulating electronics in these chips with electrical charges. And like LEDs they can be used to create color effects.

According to a Philips Lighting backgrounder, that's where the similarities end. “A key structural difference is that OLEDs are created using organic semiconductors (such as those that make up organic solar cells), while LEDs are built in crystals from an inorganic material,” says the backgrounder. “There are also visible differences between these two types of solid-state lighting. LEDs are glittering points of light - in essence, brilliant miniature light bulbs. OLEDs, on the other hand, are extremely flat panels that evenly emit light over the complete surface. The illumination they produce is “calm,” more glowing and diffuse and non-glaring.”

OLEDs are being developed by manufacturers all over the world into either rigid or flexible panels that could one day light offices, stores, cars, or even be stitched into clothing for fashion or safety or manufactured into furniture. Some enthusiasts see OLEDs being produced in razor-thin rolls, much like wallpaper, and being installed on ceilings, walls and other flat surfaces. When you need light in such as room, you would just “turn on” the wall or ceiling.

Since they produce next-to-no heat or emit much glare, OLEDs can provide up-close-and-personal illumination. Philips Lighting already has a working prototype of a mirror that senses when the person is near the mirror's surface and then provides what one Philips OLED enthusiast described as “an aura of illumination” bathing your face in a soft, pleasant light.

Joe Knisley, who has covered lighting for Electrical Wholesaling and Electrical Construction & Maintenance (EC&M) magazines since the 1960s, has seen many new technologies enter the market over the years. He agrees that OLEDs could offer soft, glareless, heat-free illumination for special applications such as shelf lighting in a retail store, wall panels and illuminating art work. He said that if the roll-to-roll manufacturing process (currently under development by GE) is perfected, OLEDs could be made in a continuous roll and could be installed similar to wallpaper.

That's the good news. The bad news is that OLEDs are extraordinarily expensive, in part because their manufacturing process requires clean rooms where workers carefully “stack” various layers onto substrates that at the present time are fairly small panels.

Some lighting manufacturers, including Philips Lighting, Osram (Sylvania), GE, WAC Lighting and Acuity Brands, have OLEDs on the market for high-end decorative applications. Right now, the high cost of OLEDs do create a bit of a buzz for zillionaires who equate cost with social status and want to have unique lighting to show off in their Aspen ski chalets or Mediterranean villas, or for some Fortune 500 companies or other global giants who want to wow visitors the their headquarters with OLED displays in their boardrooms or lobbies.

WAC Lighting, Garden City, N.Y., was one of the first lighting fixture manufacturers to utilize OLEDs in its fixtures, and in 2010 showed off its SOL chandelier (see photo above) at LightFair in Las Vegas. The chandelier made a statement with its radical design and pleasing light — and its price tag, which at the time reportedly topped five figures.

Dietmar Thomas, a communication specialist specializing in OLEDs for Philips, says his company has been making OLEDs for display applications since 1991 and for lighting applications since 2004. He says that to date, Philips' OLEDs, including its Lumiblade product, have been used mostly in corporate headquarters, airport lounges and in residential homes owned by the super-rich. He says lighting designers and architects already using OLEDs in their lighting designs love them for the quality of the light they produce. Thomas said it's important to realize that OLEDs are not a successor to LEDs, but a completely new light source that will compete for attention and market share with LEDs.

He says OLEDs cannot yet compete on price or on lumen output (the amount of illumination a lighting source produces), but that as the cost of manufacturing OLEDs come down, Philips is preparing for the day when they are priced more competitively and can produce as much if not more light than LEDs and traditional lighting sources like fluorescent, incandescent and halogens. The company is now spending €40 million (US $53.2 million) on an expansion of its existing OLED product facility in Aachen, Germany. When Philips announced the plant expansion, Rene van Schooten, general manager of the Lamps business unit at Philips Lighting said in a press release, “The thin, flat nature of OLEDs makes it possible to use and easily integrate light in furniture, walls, ceilings or floors in ways that are impossible with other light sources. This additional investment in the OLED production facility at Aachen will strengthen Philips' leadership in bringing lighting innovation to the market, enhancing our ability to offer customized and innovative OLED lighting applications.”

Dietmar Thomas says the plant expansion will help Philips hit the mass market with OLEDs in three years. “The first step is going to be with OEMs, to be available for office and retail applications on a large scale by 2015-2016. You can expect us in the hardware stores (distributors and other sales channels) by 2018.

“Our main issue is that people love the lighting produced by OLEDs. It's the first complete surface light source, while all other light sources, including LEDs are point light sources. That's the big difference.”

OLED lighting has attracted plenty of interest from the large lighting manufacturers, as well as from a dizzying array of semiconductor and electronics components manufacturers that had previously focused on OLED displays and are just now looking seriously at extending their product lines into OLED lighting. According to www.oled-info.com, the following companies are currently developing OLEDs: AU Optronics of Taiwan, Kaneka Konica, Lumiotec, Minolta, Mitsubishi, NEC Lighting, Pioneer, Panasonic and Sumitomo of Japan; Doosan Electronic and ModisTech of Korea; First-o-lite of China; Germany's Ledon OLED Lighting; and OLEDWorks, which was established in 2010 by former Kodak OLED employees

As mentioned earlier, in the United States, Acuity Brands, GE, Osram Sylvania, and WAC Lighting are all involved with OLEDs. Last year, Acuity Brands' Revel, a modular OLED lighting system marketed under the company's Winona brand, won LightFair's prestigious 2011 Most Innovative Product of the Year award, and was recognized by the Illuminating Engineering Society (IES) in its 2011 Progress Report as the first OLED surface-mounted general illumination luminaire. The report said Revel is also suitable for specialty and decorative lighting in conference rooms, reception areas and other spaces. The IES also recognized WAC Lighting's SOL chandelier (mentioned earlier) in its 2011 Progress Report as “the first commercially available OLED chandelier,” and said SOL delivers total light output of 420 lumens.

One of the biggest challenges for the OLED market is the high cost of manufacturing the panels. As it does with other energy-efficient electrical products and technologies such as photovoltaics and electric vehicles, the U.S. Department of Energy (DOE) is funding the development of more efficient manufacturing processes for solid-state lighting including OLEDs and LEDs by U.S- based manufacturers. DOE is allocating $10 million in funds in its latest round.

As OLEDs evolve, enthusiasts expect them to eventually compete with traditional lighting sources on price, energy efficiency and overall quality of light. But they will have to get larger, as currently OLEDs are only available in fairly small panels. According to a report at www.oled-info.com, Philips believes that by 2018 it will have 1-meter by 1-meter flexible panels available. Its Lumiblade modules are currently 70mm-by-70mm (approximately 2.75 inches square).

Lighting manufacturers will really need to improve their efficacy (amount of light) as compared to conventional light sources. Some OLEDs currently produce only 15 lumens/Watt, which is just a bit better than today's incandescents. The article posted at www.oled-info.com on Philips Lighting's OLEDs, said that the 1,000mm-by-1,000mm OLED panels it expects to have in the market by 2018 will only produce 35 lumens/watt, well under the 70-100 lumens/Watt that fluorescent lighting systems now produce.

That being said, OLEDs will be a fascinating product segment to follow over the next few years. It will take years — if ever — before they pencil-out against fluorescent lighting systems for general office illumination. But the radical design advantages OLEDs offer, including their ability to produce a soft aura of glare-free light, no cumbersome lighting fixtures or heat sinks and the option of flexible lighting panels, will wow many lighting designers and architects.

There seem to be two camps in the lighting industry. You have the enthusiasts who believe OLEDs will one day compete with traditional lighting sources in many applications, and then there are the skeptics that think OLEDs will never be competitive with existing light sources or with other developing lighting technologies like organic light-emitting transistors (OLETs), carbon nanotubes or light-emitting electrochemical cells (LEECs), in either cost or quality of light.

That being said, the major lamp manufacturers and semiconductor manufacturers wouldn't be spending millions on OLED R&D if they did not see some potential. You may not stock OLEDs on your shelves anytime soon, but it never hurts to get an early heads-up on a radically new product that could really separate you from the pack some day.