17 Projects Shaping the Future of LED Lighting

Posted on Jul 07, 2010 in Science & Technology

Source: Popular Mechanics

Solid-state lighting holds the promise of huge energy savings and long-lasting light sources. But before it comes to market, the products, like LED lights, have to get better, cheaper and easier to make. Here’s how the U.S. Department of Energy is investing in a future illuminated by light-emitting diodes (LEDs) and organic light-emitting diodes (OLEDs).

Over the next decade, the familiar ways we light our world, from incandescent light bulbs to overhead fluorescent tubes, may go the way of the oil lamp.

At least that’s the future envisioned by the Department of Energy (DOE). The agency announced $37 million in grants earlier this month in its sixth round of funding for solid-state lighting. The cash will go toward basic research, product development and manufacturing of light-emitting diodes (LEDs) and carbon-containing organic light-emitting diodes (OLEDs).

Together, these light sources offer huge advantages over conventional lighting. “[LEDs and OLEDs] can be more efficient than any light source available,” says Jim Brodrick, lighting program manager for the DOE’s office of Energy Efficiency and Renewable Energy (EERE). Compared to incandescent bulbs, solid-state lighting can be 10 times as energy-efficient and last hundreds of times longer. And LEDs can already easily triple the 10,000 hours or so of lifetime for compact fluorescent light bulbs, which are in today’s lighting vanguard. Meanwhile, extending the life of OLEDs is a hot area of study that the DOE’s grants will intensify.

LEDs and OLEDs are also durable, unlike incandescent lights with their fragile, superhot tungsten filament surrounded by glass bulbs, or fluorescent lighting’s glass tubes that contain small amounts of energized mercury vapor. Most LEDs and OLEDs are tiny wafers—”they look like a squashed pea,” says Brodrick—made of semiconducting metallic compounds, usually surrounded by hard plastics. “Solid-state lighting gets away from the motif of lighting as breakable,” Brodrick says.

Beyond toughness and cost savings, the environment stands to gain from mercury-free solid-state lighting as well. Widespread deployment by 2030 could cut U.S. electricity use for lighting by a third, according to the DOE, and thus make a big dent in energy-related carbon emissions.

Given these major benefits, LEDs are already the light of choice for traffic signals and flashlights. (They have actually been used as red indicator lights on remote controls for decades.) But LEDs and OLEDs have so far failed to make serious inroads into residential and commercial lighting primarily because of cost and color.

Solid-state lighting available on the market today costs roughly three times as much as other lighting options, Brodrick says. This is largely due to the materials involved and the limited economies of scale compared to the long-established techniques for manufacturing incandescents and fluorescents by the hundreds of millions every year.

LEDs also have problems with light color—their whites appear too bluish and thereby render other colors poorly compared to traditional bulbs.

To address these issues, the 17 solid-state lighting grants issued by the DOE were awarded based on three categories. Core Technology grants totaling $4 million intend to fill in key technology gaps and expand the knowledge base. The DOE will sink $10.3 million into product development to refine products to be more functional, market-friendly and commercially viable. And for the first time, the DOE solid-state lighting grants will include a manufacturing category with $23.5 million to dole out.

Collectively, these grants seek to drive down costs while improving quality and developing new product-making techniques. The chosen companies will also chip in large sums of cash on their projects, bringing the whole solid-state research program to upwards of $66 million.

Here’s a breakdown of how some of these 17 projects will bring about the next generation in lighting.

Core Technology ///

Grant Recipient Project Description DOE $ Total Project Value
Cambrios Sunnyvale, CA Solution-Processable Transparent Conductive Hole Injection Electrode for Organic Light-Emitting Diode (OLED) SSL. This project seeks to develop a cost-effective replacement for indium tin oxide for use as an electrode in OLED lighting devices. Indium is both rare and very expensive. $1,199,971 $1,846,110
University of Rochester Rochester, NY Development and Utilization of Host Materials for White Phosphorescent OLEDs. This project seeks to produce white OLEDs with > 100 lm/W efficiency after light extraction enhancement and > 10,000 hour operating time, by making a new class of emissive materials. $1,239,071 $1,376,746
WhiteOptics, LLC Newark, DE Low-Cost, Highly Lambertian Reflector Composite for Improved LED Fixture Efficiency and Lifetime. This project seeks to demonstrate a highly reflective, highly diffuse, low-cost composite material that is able to withstand at least 50,000 hours of luminaire operation. $1,556,316 $1,967,373

Cheaper Electrodes

The Cambrios company, out of Sunnyvale, Calif., is hoping to develop a new electrode for energizing OLEDs that’s cheaper and better than the indium tin oxide used now. The trick will be finding “a new substance that’s transparent and also conducts electricity,” Brodrick says.

Evenly Dispersed Electrons

Another technical challenge will be spreading electrons that are introduced at the corner of an OLED square evenly across the whole sheet of material. The University of Rochester will tackle this problem with an emphasis on improving light extraction from OLEDs with new materials. Just like regular LEDs, these thin lighting sources absorb some of the photons (particles of light) they produce, so different coatings and structural add-ons—such as “photonic lattices” which are full of holes that channel light out—continue to be investigated.

Higher Output

To boost output from the rest of a light-emitting fixture, the Delaware-based company WhiteOptics makes a special plastic that reflects 97 percent of light in a diffuse, eye-friendly manner. This could be significant for LEDs because they are typically point-sources of light, cranking out a lot of lumens from a bright, hot area that is mere millimeters square, says Eric Teather, founder and president of WhiteOptics. Lighting designers often place multiple LEDs in clusters to produce the equivalent of other lighting sources, but this can give the light a piercing, pixelated appearance. “People are not used to seeing dots; they want to see uniform, well-distributed light,” Teather says. Lenses are sometimes placed over the top of the LEDs to direct and disperse the light, but these can cut into output, Teather says.

The DOE grant to WhiteOptics will go toward improving the reflectivity of the company’s proprietary material, which can further reduce the number of individual LED chips needed in a fixture. Teather says he has concept materials that reflect 99 percent of incident light. WhiteOptics has previously demonstrated that its reflective plastics can improve lighting efficiency by 15 to 20 percent. These efficiency gains cut almost dollar-for-dollar into overall costs, Teather says, because the most expensive part of an LED fixture is the LEDs themselves, with the reflective plastic coating just a fraction of the overall price. In addition, the reflective plastic will be geared for long life—50,000 hours, or pushing six years—and will be low-cost. Teather expects to deliver on this technology in about three years.

Product Development ///

Grant Recipient Project Description DOE $ Total Project Value
Cree, Inc.
Durham, NC
Ultra-Compact High-Efficiency Luminaire for General Illumination. This project seeks to create an ultra-compact 80-lm/W SSL luminaire that emits at a color temperature of 3000K with a CRI of 90. The integrated approach will establish a technology platform capable of providing high-efficiency LED components that can be adopted across a variety of SSL applications.  $1,799,962 $2,337,613
General Electric
Niskayuna, NY
Optimized Phosphors for Warm-White LED Light Engines. GE Global Research, in collaboration with GE Lumination and the University of Georgia (UGA), seeks to develop optimized phosphor systems and packaging for LED down-conversion. $1,774,565 $2,535,095
Lightscape Materials, Inc.
Princeton, NJ
Nitride- and Oxynitride-Based Phosphors for SSL. This project seeks to develop a set of high-efficiency, novel nitride- and oxynitride-based phosphor products. $1,794,806 $2,243,507
Osram Sylvania Products, Inc.
Beverly, Mass. 
High-Flux Commercial Illumination Solution with Intelligent Controls. This project seeks to create a replacement solution for fluorescent luminaires that consists of intelligent control electronics, three linear LED modules using remote phosphor technology, and a power supply, all enclosed in a metal housing. The intelligent controls will sense occupancy and ambient lighting conditions and then, to gain additional energy savings, will use switching and dimming that’s not possible without degrading fluorescent lamp performance.  $1,439,794 $1,799,742
Philips Lumileds Lighting Company, LLC
San Jose, Calif.
130 Lm/W, 1000 Lm Warm-White LED for Illumination. This project seeks to develop an illumination-grade LED having a warm-white color range, comparable output to a 75 watt incandescent lamp, and an efficacy of 130 lm/W. $1,837,168 $2,296,460
PPG Industries
Cheswick, PA
Low-Cost Integrated Substrate for OLED Lighting. PPG Industries, Inc., Glass R&D plans to develop a new low-cost integrated substrate product that is suitable for OLED lighting manufacture and is compatible with PPG’s existing flat-glass and transparent-glass coating technologies and high-volume glass manufacturing methods. $1,672,090 $2,140,062

Taking the Heat out of Home Fixtures

The grant awarded to Cree, in Durham, N.C., will help the company further develop “ultra-compact” LEDs that could screw into existing home light fixtures while maintaining colors and high efficiency. The difficulties in making LEDs compatible with everyday fixtures is that their heat is not sent “forward” along with their pure visible-spectrum light. Instead, the heat comes out the back of the LED where it must be absorbed in a heat-sink material, such as aluminum, and dissipated.

Less Heat, More Energy

Similarly, with one of its grants, Philips Lumileds Lighting Company will tackle heat issues—making use of excess temperatures to increase the electrical current for increased lumen output. (A lumen is a measure of light as perceived by the human eye. The efficiency of a bulb is scored as the amount of lumens that can be gleaned from a single watt, or unit of energy conversion.) Philips Lumileds’ project aims for a hefty 130 lumens per watt. In comparison, Brodrick says standard incandescent bulbs put out about 12 to 15 lumens per watt. That’s because about 90 percent of the energy that goes into them is wasted as heat. And while fluorescent tube lamps and twisty compact fluorescent lights perform much better, they’ve reached their physical limitations, Brodrick says, and any efficiency gains won’t be able to match solid-state lighting.

Color Corrections

The lighting-color problems that have plagued less efficient fluorescents have also dogged LEDs, and several grants seek to address this deficiency. The majority of LED fixtures and devices make icy white-blue light, “and things don’t look that vibrant under that white light,” says Anant Setlur, a materials scientist at General Electric. However, these white-light LEDs very efficiently convert electrical energy into light. So the goal is to lower blue LEDs’ color temperature into more reddish and warm values.

To do this, some awards, including one of GE’s, go toward developing the next generation of phosphors. These are substances that absorb light produced by a source and then re-emit light out of the product with desired lighting characteristics. For example, phosphors are what make the invisible, harmful ultraviolet light generated by energized mercury vapor in fluorescent lights come out instead as a safe, if somewhat sterile, white-blue that we can see. GE will investigate both novel phosphors and mixes of existing phosphors (turning some blue light to green on into yellow, for example) to achieve final desired lighting color.

Everlasting LED

Osram Sylvania’s grant will be applied to with replacing the 3- to 4-foot long, linear fluorescent tubes that hum above many office workers’ desks with long-life LEDs. These lamps will be manufactured to last up to 100,000 hours, or over 11 years. The lights would be part of an intelligent system that dims or turns off based on where employees are located in the office. Motion-sensor systems now in use with existing fluorescents don’t have much resolution: Walk toward your cubicle after-hours and an entire darkened wing of the office might light up. To fix this, Osram Sylvania plans to place more sensors on-site and link them up with better software. This advanced “cloud dimming” system can’t work for fluorescent lights because their lifetimes degrade with every on-off event. With LEDs, however, such a system would actually “improve life because when they’re off they’re not aging,” says Jim Frey, part of the DOE LED project team at Osram Sylvania. Although pricey up front, this lighting system solution would pay for itself within several years, says Rob Harrison also of Osram Sylvania. Such a system could come be on the market toward the end of the project’s two-year timeline.

Manufacturing ///

Grant Recipient Project Description DOE $ Total Project Value
Applied Materials, Inc.
Santa Clara, CA
Advanced Epi Tools for Gallium Nitride LED Devices. This project seeks to develop an advanced multichamber hybrid epitaxial growth system for LED manufacturers that has the potential to decrease operating costs, increase efficiency of LEDs, and improve binning yields.  $3,993,911 $8,718,911
GE Global Research
Niskayuna, NY
Roll-to-Roll Solution-Processable Small-Molecule OLEDs. This project seeks to upgrade GE’s prepilot OLED roll-to-roll manufacturing line through improved high-performance phosphorescent small-molecule OLED materials, advanced OLED device architectures, plastic ultra-high barrier films, and an advanced encapsulation scheme. $3,999,966 $7,999,932
GE Lumination
Valley View, OH
Development of Advanced Manufacturing Methods for Warm-White LEDs for General Lighting. This project seeks to develop precise and efficient manufacturing techniques for GE Lumination’s “remote phosphor” platform of warm-white LED products named Vio™. The approach drives significant materials, labor, and capital productivity to achieve approximately 53% reduction in overall cost, while minimizing color variation in the Vio platform. $772,425 $1,544,850
KLA-Tencor Corporation
Milpitas, CA 
Automated Yield Management and Defect Source Analysis Inspection Tooling and Software for LED Manufacturing. This project seeks to improve the product yield for high-brightness LEDs by developing an automated optical defect detection and classification system that identifies and distinguishes harmful defects from benign defects. The proposed approach allows for traceability in defect origin and includes the hardware and correlated software package development.  $3,484,045 $6,968,091
Philips Lumileds Lighting Company, LLC
San Jose, CA
Low-Cost Illumination-Grade LEDs. This project seeks to realize a 30% yield improvement and 60% reduction in epitaxy manufacturing costs for highpower LEDs through the implementation of silicon-based epitaxial processes on large-diameter substrates. The use of silicon replaces the industry standard sapphire or silicon-carbide substrates. The process will be developed using Philips Lumileds’s proven LUXEON® Rebel LED. $1,907,963 $3,815,926
Ultratech, Inc.
San Jose, CA
A Low-Cost Lithography Tool for High-Brightness LED Manufacturing. This project seeks to develop a lithographic manufacturing tool having the benefits of higher throughput, greater yields, lower initial capital cost, and lower cost of ownership. A projection stepper process will be modified and optimized for LED manufacturing. The proposed system will be able to accommodate a variety of wafer sizes and thicknesses and handle the wafer warpage typically associated with larger-diameter substrates. $1,295,634 $2,364,327
Universal Display Corporation (UDC)
Ewing, NJ
Creation of a U.S. Phosphorescent OLED Lighting Panel Manufacturing Facility. This project seeks to design and set up two pilot phosphorescent OLED (PHOLED) manufacturing lines. The team will implement UDC’s PHOLED technology and provide prototype lighting panels to U.S. luminaire manufacturers to incorporate into products, to facilitate testing of design, and to gauge customer acceptance. $4,000,000 $8,304,470
Veeco Instruments
Somerset, NJ
Implementation of Process-Simulation Tools and Temperature-Control Methods for High-Yield Metal Organic Chemical Vapor Deposition (MOCVD) Growth. This project seeks to develop a complementary set of high-resolution short-wavelength and infra-red in-situ monitoring tools for accurate substrate temperature measurement and growth rate monitoring. Philips Lumileds will test the resulting tool in the processing of LEDs. The approach is anticipated to result in a 100% improvement in wavelength yield and a 75% cost reduction for LED epitaxy. $4,000,000 $8,000,000

Home-Grown LEDs

Cost reduction is the name of the game for all of the projects in the DOE’s manufacturing grants. To do this companies can find cheaper materials or, as Applied Materials in Santa Clara, Calif., plans to do, can work on making the manufacturing process cheaper. Applied Materials is looking into an epitaxial method for “growing” LED chips layer by layer in a multichamber system that will increase throughput, to turn around a batch of LED wafers much more quickly than is currently possible.

The Silicon Solution

Philips Lumileds, another nearby Silicon Valley firm referenced previously, is also looking to upgrade epitaxy. They plan to replace industry-standard sapphire and silicon-carbide substrates for LED wafers with much cheaper silicon. LED makers currently use wafers around 2 inches in diameter, like the fledgling computer microchip industry did back in the 1970s. Nowadays, microchip manufacturers have vastly increased yield per wafer by working their way up to 12-inch and even 16-inch wafers; LED makers look to do the same, but will have to work within silicon’s crystal structure, Brodrick says. “A number of groups have taken a crack at silicon,” he says, without much success.

Defect Finder

For quality control of these future silicon and current sapphire wafers, KLA-Tencor was awarded half of a $7 million project to build an automated optical-defect detection system. The system is basically an electronic “eye” that spots damage on substrates down to billionths of an inch prior to beginning the manufacturing process. This weeding out will avoid time and money wasted building an LED on a faulty substrate while ensuring that the ultimate product works to specs.

Paper-Thin OLEDs

Back east in Niskayuna, N.Y., at GE’s global research headquarters, the company plans to take advantage of LEDs’ less expensive, organic cousins, OLEDs, which can be made paper-thin and in long, bendable sheets. Two years ago, GE, in collaboration with the government and another company, showed that these OLEDs can be manufactured roll-to-roll, much like a newspaper printing press. Essentially tied with the largest of the DOE grants at a hair shy of $4 million, these funds will help GE improve its manufacturing line in the hopes of cranking out thin sheets that illuminate with the application of an electric charge. According to a video on GE’s Edison’s Desk blog, applications include light-up wallpaper plus glowing decals and light strips that can be contoured to fit pretty much anywhere.

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