Until the past few years, electric lighting has slowly, steadily evolved from incandescents to fluorescents and LEDs. But today, a variety of new technologies promise to offer either efficiency or new light experiences, sometimes in places lighting couldn’t be installed before. LEDs still represent the most revolutionary recent change in light fixtures, but it has also paved the way for new, complementary technologies.
Some lighting alternatives show staying power. Others face a steep climb to wide-scale commercial adoption. Organic LEDs (OLEDs) are one alternative that can be installed in places and ways traditional lighting never could.
Over the last decade, OLED technology has been a focus of research and development, and it is seeing its way into commercial installations. This light source can be made flat and flexible, introducing radical new possibilities for lighting installations. The central feature of OLED is suffused light, contrasting with the pinpoint illumination of LED.
The OLED’s history dates back a few decades. Physical chemists at Kodak developed the technology in 1987. The lamp substrate they designed consists of a layer of organic conductive materials sandwiched between two electrodes. The fixture is thin but offers a wide, diffused source of light.
Up to this point, OLED technology has been used predominantly in electronics displays, but companies are also selling it for interior and exterior architectural lighting. Developers began experimenting with OLEDs in lighting fixtures about eight years ago. However, in the last three to four years the overall value proposition—between performance and cost—has started to make sense for those considering deployment.
Today, OLED installations can be found in indoor and exterior lighting for residential, office, industrial, outdoor, hospitality, shop and automotive applications, according to market research firm IDTechEx. The analysts expect the OLED market to grow to $2.5 billion by 2027, globally, in an optimistic scenario, while there is still likely to be slow adoption until 2020 or later. Architectural, hospitality and shop segments are likely to be the fastest adopting industries, while residential, office and outdoor lighting will follow as costs drop and the lifespan of the fixtures increases.
With growth in mind, some companies have begun selling OLED technology, while startups have recently opened as well. OLEDWorks in Rochester, N.Y., is one such example that offers a range of OLED products. The company develops and manufactures light panels that emit red, amber or full spectrum white light for commercial spaces, offices and hospitality.
OLEDs and LEDs are fundamentally similar. However, the OLED lighting experience contrasts sharply with LED.
“Both technologies are solid-state diodes,” said Giana Phelan, OLEDWorks director of business development. “While LEDs are tiny point sources that require optics and wave guides to distribute the light and heat sinks to manage the temperature, OLEDs are thin, large-area sources that do not need optical or thermal management.”
The light is naturally diffuse and can be tuned for spectral radiance. In contrast to LEDs that require phosphors for spectrum control, OLEDs’ color temperature is produced by employing different organic emitter materials in electroluminescent layers.
While the OLED is still in its infancy, it is evolving at a faster rate than LEDs did (they required about four decades to gain significant traction). That makes OLED growth that much more interesting, said Jeff Jackson, OLEDWorks director of prototype development, since it was first developed about 30 years ago, and installations are already in place in a variety of venues.
However, OLEDs’ biggest drawback is expense. To light up a large public space or room, the cost could still be prohibitive in many cases. Price may not be the point, however, for users prepared to pay more for the quality of the light.
“I wouldn’t say it would replace a $10 lamp right now. It’s not that kind of product,” Phelan said.
Instead, it’s about the aesthetics. OLEDs are designed to fill the volume of the room with light, leaving no dark corners, and no shadowing.
“The light quality is a high-quality diffused source that’s easy on the eyes, low glare; it feels better,” Phelan said. ”It’s a very good lighting experience.”
The performance rivals LEDs. Currently, the lamps are achieving up to 85 lumens per watt for warm, white color with lifespans pushing 100,000 hours.
Where other lighting won’t fit
The OLED’s form factor provides another incentive for some installations. The ultra-thin fixtures can be installed where LEDs simply wouldn’t fit, Jackson said. They can be as thin as 150 microns, weigh 15 grams, and can bend as well, despite being glass, so they can be installed on curved surfaces such as a pole.
Since the light itself is cool, OLEDs can be mounted directly on the surface of a ceiling or wire—no junction box required.
ECs will find OLEDs easy to install. In fact, they can be installed with Class 2 circuits, Jackson said, similar to any low-voltage installation for lighting controls or communications accessories.
“For the most part, contractors love them because they’re easy to mount. It is a simple low-voltage installation,” Jackson said.
In cases in which contractors are already installing low-voltage systems, such as security cameras, the OLEDs serve as a straight-forward add-on to that installation.
To acquaint themselves with OLEDs, ECs should start with the basics.
“I would highly recommend that contractors read the instructions provided by the manufacturer,” Phelan said. “It can be pretty basic stuff, but some care has to be taken since OLEDs are glass surfaces.”
While Phelan hasn’t seen panel cracking in installations, she said it’s a possibility. To make the process easier, OLED manufacturers offer training.
“We do workshops and encourage contractors to come,” Phelan said. “We also offer to assist with training and are open to more interactions in the future.”
Phelan noted, whether or not ECs have yet encountered OLEDs, they should plan for OLED customers within the next one to five years.
OLED manufacturers sometimes partner with mounting and electronic development companies, such as LED Specialists Inc. OLED panels are very thin—2 millimeters, available in square 120.5-by-120.5-, rectangular 62.7-by-240.6- or 113-millimeter diameter round panels.
LED Specialists, founded in 2004, initially provided LED lighting product development services based on LED technology. Bill Reisenauer, founding partner at LED Specialists, said his company teamed up with OLEDWorks to offer customers turnkey lighting solutions. The company has designed LED lighting systems for applications ranging from the Boeing 737 aircraft to architectural, marine, mining and retail environments. In 2006, LED Specialists expanded into the UV market with development services and products for UV curing and UV disinfection for healthcare companies such as Cardinal Health and CleanCo Bioscience Group.
About two years ago, the company approached the New York State Energy Research and Development Authority (NYSERDA) with a concept to enable adoption of OLED technology and panels. The company was interested in the technology’s potential environmental benefits and environmentally friendlier materials. LED Specialists partnered with NYSERDA to develop and build electronic drivers and mounting accessories to support the new lighting technology.
LED Specialists is now an authorized distributor of OLEDWorks products. It also sells its own drivers and OLED developer’s kits. OLED flat-glass panels require some way of mounting and powering. That is also where LED Specialists often comes in.
“We have developed thin, miniaturized driver electronics and a cradle—a two-piece fixture that the glass panel mounts into,” Reisenauer said.
The cradle assembly provides contractors with the option of mounting the panels to a junction box or on a flat surface. Reisenauer said customers seek OLED installations because they are drawn to the panel’s thinness and light’s aesthetic. OLED panels are available with a frosted or mirrored finish. The near-term future promise of flexible panels opens additional opportunities for applications on poles or other shaped surfaces.
Soft and gentle
Acuity Brands has been selling OLED luminaires for nearly a decade and mainly to companies seeking more than simply functional lighting; rather, a lighting experience.
“Acuity publicly demonstrated its first OLED luminaires in 2010,” said Jeannine Fisher Wang, director of design partnership for Acuity’s Custom Architectural Lighting Solutions (CALS). “And we’ve seen an evolution in the technology as well as improvement in performance.”
The lighting has been installed on or in low ceilings as well as commercial locations such as the entry vestibule for a Rochester Wegmans store. No other technologies offer a paper-like sheet of diffused light.
“It provides an aesthetic that envelops us,” Fisher Wang said. “It’s a soft, gentle light.”
It goes beyond the diffused nature of OLED illumination. The light-emitting layers of an OLED device are synthesized out of organic materials primarily made up of carbon and hydrogen. These materials are layered upon a substrate that can be either rigid or flexible, defining the possible form factors and applications for use. There is inherently more flexibility in design when designers and contractors have more tools at their disposal.
“The color characteristics are based on the materials that are encapsulated in the device,” Fisher Wang said. “You can be very innovative in applying various layers of OLED and LED lighting in a space, to create the best lighting experience.”
Installation doesn’t vary significantly from traditional LED fixtures. For design-build projects, said Ron Schimmelpfenning, VP of CALS at Acuity, the photometric files used to plan OLED light installations are no different than that used for LEDs or fluorescents. But aesthetically, that’s where the similarities end.
“You work with the same principles—lumens, foot-candles, luminance,” he said. “What’s special about OLED is in the inherent lack of glare and the sleek designs.”
Schimmelpfenning agreed that most contractors should prepare for OLED installations.
“I would recommend keeping any eye on it,” he said. “Contractors make a lot of buying decisions, and knowledge of OLEDs will allow them to pick up their game.”
LEC and quantum dots
OLED isn’t the only technology that is vying for a place in the lighting market that LEDs now dominate. Another alternative is the light-emitting electrochemical cell (LEC). Compared to OLED, the LEC is inexpensive to produce. It consists of a transparent electrode made of carbon material graphene. Graphene is not only strong, but acts as an electrical conductor. Because it’s carbon, graphene can be easily recycled, and researchers have showed that it can be produced as a solution in the form of graphene oxide, making manufacture much easier.
Then there’s the quantum dot. These are tiny crystals of semiconducting material just a few tens of atoms across. They are typically made by combining zinc, cadmium, selenium and sulfur. When excited by electricity, the dots emit light of varying colors depending on the size of the dot and material used.
A handful of companies are developing quantum-dot films that shift the light of blue LEDs to a more natural light that has a warm feel. This experience may be important to fueling adoption for general purpose lighting.
According to Reisenauer, Quantum holds a lot of promise but it’s been hitting obstacles, in part just getting the cost down to a point where Quantum dots are realistic for commercial deployments.