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Soraa, Bridgelux, and Osram battle for the LED substrate crown.
A four-way LED substrate battle is shaping up among sapphire, silicon carbide, silicon, and gallium nitride materials.
The prize is much cheaper LED chips and lighting products.
Soraa’s recent unstealthing added gallium nitride (GaN) to the active contender list with its GaN-on-GaN device. On the silicon (Si) front, Osram Opto CTO Ulrich Steegmueller presented the company’s Si research at a recent lighting event. Bridgelux, also researching silicon, raised $25 million in funding from China.
There are some dark horses, including glass, germanium, and aluminum nitride (AlN).
Nitride Solutions of Wichita Kansas closed an oversubscribed $2.5 million round A this month for AlN substrates, with an ultraviolet market emphasis.
High brightness LEDs (other than red) are derivatives of gallium nitride. As with semiconductors, generally, you want to build on a stable substrate with an accurate crystal lattice, but gallium nitride is unstable and defect-ridden. The stable alternatives have a lattice spacing mismatch with the GaN and the result is shattered wafers and efficiency loss. A variety of coping techniques have evolved, such as buffer layers. (For a readable backgrounder on the topic, see here.)
The status quo is sapphire. But the cost of making LEDs out of synthetic gemstones has drawn in the other contenders.
- Sapphire: the defender. Users are almost everyone but Cree; Lattice mismatch: 13 percent; Advantage: Stable, mismatch well researched; Disadvantage: Too expensive for what you get; Bottom Line: Will never meet DOE’s 20X cost reduction goal.
- Silicon Carbide: the Macintosh of substrates. Users are mainly Cree; Lattice mismatch: 3.5 percent; Advantage: Very stable. Low mismatch aided by cancelling thermal mismatch, highest thermal conductivity; Disadvantage: Priciest, almost proprietary; you may have to buy it from your toughest competitor; Bottom Line: Relatively less costly and difficult if you’re Cree, costlier and harder if you’re anyone else. Cree was a silicon carbide company before becoming an LED company.
- Silicon: Users — Research maturing in Osram Opto, Bridgelux, China; Lattice mismatch:17 percent (plus a 56 percent additive thermal mismatch); Advantages: 80 percent substrate cost reduction potential, ubiquitous, big wafers; Disadvantages: Lattice and thermal expansion mismatches from hell.
- Gallium Nitride: Users: Soraa; Lattice mismatch: 0 percent; Advantage: Lattice and thermal match from heaven, homogeneous material allows higher drive level by tuning the GaN for reduced droop; Disadvantage: Unstable, defect-ridden; Bottom line: Analogous to Cree and silicon carbide, relatively less costly and less difficult if you’re Shuji Nakamura, Steve DenBaars, and Jim Speck, much worse if you’re anybody else.
Soraa is performing a bit of a head fake by not selling LEDs, shipping only a finished MR16 halogen reflector where their compact die is able to win with superior beam concentration. However, that is essentially how all LEDs compete with high pressure sodium lamps to this day.
While we shouldn’t get ahead of ourselves, new substrates could turn some non-adapting companies into stranded whales. Cree may have a particular hazard here, with a unique, almost emotional, commitment to silicon carbide. On the principle that any new substrate will only be adopted if it has a cost or performance advantage, the battle of the substrates will, in the end, only accelerate and enhance the inevitable transition to solid-state lighting.
By: DOUG WIDNEY
Lemnis Lighting is taking a foot-in-the-door approach to LED lightbulbs.
The startup company today announced a new line of bulbs, priced at $4.95 and $6.95, respectively, aimed at getting consumers to try out LEDs for general lighting. The bulbs, though, have some limitations.
The Pharox Blu line comes in 200-lumen and 350-lumen versions, both of which give off less light a 40-watt incandescent bulb’s 450 lumens. That means that the bulbs, which consume less than 5 watts and 8 watts, respectively, won’t give off enough light for many uses, such as lighting a whole room.
The Blu line also has a one-year warranty, versus a three-year warranty for existing Pharox line. They don’t work with a dimmer, a move to save money on manufacturing.
Lemnis is deliberately taking a no-frills approach to get consumers familiar with LED lighting, said Lemnis Lighting co-founder Warner Philips. “Customers want higher-lumen products, but they also want a model that gets them in the game and starts them testing LEDs,” he said.
In the past two years, large lighting companies have introduced LED bulbs able to give off as much light as a 60-watt or 75-watt incandescent priced around $35 or $40. They use about 80 percent less power than incandescent bulbs and are designed to last 15 to 25 years, depending on usage.
Based on online reviews, consumers who have bought LED bulbs are generally happy with the performance of the products. And costs have fallen significantly over the past several months, aided in some places by state or utility rebates.
But most consumers are not willing to do the math on how quickly LEDs pay for themselves in energy savings, Philips said. That’s causing concern in the lighting industry over how strong consumer demand is for general-lighting LEDs.
Even though they give off relatively little light, Philips suggested that the new Blu bulbs can be used for downward directional lighting in offices or in recessed cans in a kitchen. Both will be sold only through the company’s Web site, with sales yielding a low-margin profit, Philips said.
Lemnis is working on brighter LED bulbs too. In the second quarter, it plans to introduce three higher-priced models with a lighting range between 400 lumens and 800 lumens, or roughly from that of a 40-watt to a 60-watt incandescent. Prices for those will start around $10, be dimmable, and have a longer, three-year warranty, Philips said.
By: Martin LaMonica
An end product’s supply chain can be far reaching, with parts or all of the upstream and downstream producers sometimes getting hit at different times by economic forces.
This appears to be happening in China’s domestic LED market, which has seen a marked fall-off in demand, according to the China Strategic Monitor. That’s hit pricing during the second half of this year.
“Investment plans are being curtailed both in the upstream and downstream compared to those presented last year,” according to the report. “Despite this there are many companies still attracted to the market and many pharmaceutical companies and even wineries in South China are moving into LED lighting products. Based on this trend the industry is likely to realize large-scale production capacity over the next 2 or 3 years and pricing for products should fall a further 20-30%.”
Industry watchers reckon 10% of LED-driven businesses in China could go bankrupt this year. And one chief executive, speaking at the recent China Industrial Development Forum for the Low Carbon Economy, said 90% of all China’s LED businesses are running at a loss.
Interesting. The country’s Guangdong province said earlier this month that it had exported US$3.81 billion worth of lighting products between January and August – that’s a 21% increase over the same time period last year.
“Customs authorities indicated that the main export market is still Europe and America with the two taking up 63.2% of the total,” a report said. “Though exports to Hong Kong, Japan and other ASEAN countries are up 60% on last year.”
The massive rise in LED exports is ascribed to the increasing trend of upgrading to energy-efficient lighting combined with the higher production values and quality in China, according to the report.
Still, various companies producing LED products complain that the industry is hit with high selling, raw material and R&D costs. So, while a company reports a 32% jump in LED sales in the third quarter of 2011when compared to 2Q10, the senior executives also talk about the need to implement structural changes, improve execution, reduce overhead costs and initiate job cuts.
Now, the LED industry uses a wide range of phosphor materials to convert light emission from LED chips into a different wavelength. So, combining a blue LED with one or more phosphors can create a white LED. Many of the phosphors used in LEDs contain rare-earth elements, the most common one being the yttrium aluminum garnet, which is doped with cerium. Another phosphor, called TAG, contains terbium, while silicate and nitride phosphors are commonly doped with cerium or europium.
Here’s a small example of how LED products are being used: Kingsun Optoelectronic Co has just installed more than 10,000 street lights containing one million high-efficiency white LEDs along 75 miles of roads in Shenzhen. Kingsun anticipates a 60-percent reduction in energy consumption compared to the high-pressure sodium fixtures that have been replaced in the upgrade.
And while LEDs are now widely recognized as emerging light sources for general illumination, it turns out that LED lighting can also be used in a broad range of life-science applications such as skin-related therapies, blood irradiation, pain management, hypertension reduction and photodynamic therapy, which, when combined with drugs, is finding its way into cancer research.
In other words, the LED industry is only now just starting to be exploited, meaning demand will grow across all sectors. Translation – more rare earths will be needed in producing these products as research advances are made and commercial producers become more lean and efficient.
By: Brian Truscott