Bridgelux Demonstrates 135 lm/W GaN-on-Silicon LED
LIGHTimes Staff

The LED was produced on a standard 8-inch silicon wafer. Bridgelux contends that growing GaN on larger, low-cost silicon wafers that are compatible with modern semiconductor manufacturing can deliver a 75% improvement in cost over current approaches, which commonly use 2- to 4-inch sapphire wafers. Bridgelux points out that when scaling up production, large diameter sapphire and silicon carbide substrates are costly, difficult to process, and sometimes not widely available. This has kept production costs high, inhibiting widespread adoption of LED lighting in homes and commercial buildings.

Additionally, the Bridgelux devices are demonstrating a low forward voltage and superior thermal resistance which make them ideally suited for high-performance, illumination-grade applications. Optimization of the epitaxy process on 8-inch Si wafers will make LED manufacturing more compatible with existing automated semiconductor lines. Bridgelux notes however that "A number of the processes [used to produce conventional LEDs] ... would need to be modified to eliminate some materials that are currently used, and which are incompatible with silicon substrate manufacturing."

February 24, 2011...We have always considered good quality industry events to be one of the best indicators of business conditions, not just by the attendance numbers, but more by the excitement and enthusiasm. By that measure, 2011 is going to be quite a year for the LED industry as a whole. Strategies in Light has always been the benchmark US LED event, and this year didn't disappoint, with a broad array of exhibitors, and plenty of good information in the dual track conference. If you're building something with LEDs, SIL is a good place to be to find out the latest and greatest solution element choices. We wanted to share some of what we garnered from the people, generally outside the talks, that share the excitement.

Tuesday had a number of pre-conference workshops, of which we gravitated towards the investor's forum, where a number of early stage or emerging companies had the chance to give their pitch to capital-oriented audience. Overall, you heard what you expect you might, and a few will certainly find some traction to bring another set of innovations to a willing market. Perhaps more important was a venture capital panel led by our longtime friend Bob Walker, now a Partner with Sierra Ventures, in which we heard from Mike Dauber (Partner, Battery Ventures), Annette Finsterbusch (Director, Applied Ventures), and Matthew Price (Principal, Nth Power), along with Dan Goyne, Managing Director of Canacord Genuity's Investment Banking Group, on what they are seeing, as well as what they are looking for. The great news is that they confirmed that solid state lighting is among the most exciting opportunities in clean-tech. Beyond that, four words summed things up from their view... "Capital efficiency" and "New markets" (I didn't count the 'and').

Capital efficiency was characterized as rather than the traditional "big buck burn rate" to last through the intensive R&D, the VCs want to see that a new entrant can take a modest amount of capital to prove the concept and opportunity, and then apply a substantial infusion to translate the plan into rapid positive cashflow. Think "Facebook". (Does that make it capital-efficient energy-efficiency??). "New market" was interestingly what they are not seeing, nor did we see it in the talks or on the show floor. LEDs and LED lighting are currently showing their capabilities to displace incumbent solutions, especially the incandescents right now, but it's all about the replacing them with something that looks and acts pretty similar, just more efficiently and with a longer life. But what are we doing with LEDs that simply couldn't have been done before? A flat panel TV is a little more flat, but it's not a "Minority Report" type display wall yet. "Invisible" lighting hasn't made its debut, and we don't seem to be reversing the natural aging processes by living under carefully tuned LEDs instead of fluorescents. Lets see something truly disruptive, and that changes how life is lived, and then we're talking "new" market. We don't know what it will be yet, but once it's here, we'll know it.

Products, applications and ideas

A meeting with Osram Opto is always enjoyable, as they make it a point to show what their LED models are enabling. Need to create an edge-lit architectural panel? They're happy to show you how. More lumens from a pico-projector? Got it. Looking at automotive forward lighting? Here's the Audi A8's approach, which includes selective use of differently sized and aimed emitters to allow adaptive headlight strategies (you turn, it aims), without needing a mechanical assist. Wanting to optimize growth in the commercial greenhouse? Rather than HID's green-yellow peak, how about new blue and hyper-red emitters that operate in spectrums that the plants really want to absorb. Need a goofy number of "nits" from ever fewer LEDs in your backlight panel? Oslon is here to save the day. Good stuff.

NXP, who impressed us back at Light Fair with their award-winning drivers, was there to say that while drivers are important to control the LEDs, controlling the drivers has a lot of benefits as well. Control systems, intelligence and communications all have a role in lighting integration, and NXP is emphasizing solutions for each of those pieces of the puzzle. Oh, and that award winning driver family can now handle more like 30W... let's see... 3000 lumens from your PAR-38? That will teach those pesky backdoor neighbors to peer over the fence when the motion detectors are on!

Philips Lighting shared their new Zhaga standard-derived 6000 lumen array module, and it is definitely cool looking. Didn't get to see it lit, but their professional line, including the Color Kinetics derived wall washers and color-changers have always been on target. Now (soon, actually) we will be able to light up the building facade and have a replacement module that implies multi-source procurement options. At least in theory, but it looks like a good theory.

Lighting hasn't really been part of the focus in the past for TI, but they are no strangers to bringing together solutions that depend upon LEDs (think DLP TVs). Leveraging their power-supply expertise, they are getting serious about solid state lighting, and also looking to leverage that "performance for the dollar" reputation into the full gamut of solutions elements... power, controls, drivers, communications. They are also clear on what might seem from the incumbent lighting side to be simple challenges, as they emphasized their commitment to "tame the beast" also known as the Triac dimmer.

Intematix offered up some time to discuss the Chroma-Lit remote-phosphor perspective, and clarified what they're up to in that regard. I confess that my impression from the quick Chroma-Lit exposure we had from their recent introduction was that they were bringing a remote phosphor modular light-engine solution to luminaire designers. Oops. It's about the remote phosphor panels. Tell them your emitter wavelength and the desired light output and color temp, and they'll point you to the right panel that will hit the target, time and time again in your production (they like to think of it as "the filament"). Dab of phosphor on a chip or a 2- to 12-inch slab of phosphor, with all the benefits that a remote approach brings to the table. The business model makes sense. We got it now.

We finally met Rambus in a face-to-face that answered a personal question of "who the heck are you?" We are admittedly leery of "IP-based" companies, from some past instances where folks have acquired IP from somewhere and then proceeded to sue whoever they could. While it's a legitimate model, and it was a way to reward the "inventor", we've found it noncontributory, especially when the inventor didn't actually take the idea towards the market, but merely hid it away to spring a trap when the time is right. Rambus doesn't conform to that model, from what we saw, and is really a company of inventors. An R&D and process engineering department, if you will, that puts together a technical approach, figures out how it will be built, adapts the tools, creates reference designs, and then offers the package to the industry. Their current approach is an edge-lighting technique that has translated from some previous backlight display technologies. For lighting manufacturers that are looking for a "light panel" type of luminaire approach, but who want to retain the value-add of end-to-end manufacturing, it can offer a them a optically, electrically and thermally engineered design, along with the support to bring it to their line. We can't assess the real market advantages that the solution they are showing today might be, but as their prospects turn into licensees, we'll all find out together. Their $2 billion-ish market cap suggests they have a lot to back up their technology, so we expect they will be a company to watch as the market marches forward.

In the "different approach" department, Israel-based Oree (that's an O, not an C) shared an update on their planar LED technology. We had written about their design last year, and it continues to impress. In simplest terms, instead of packaging a single or multi-die LED with a dome type lens, they sandwich a playing card sized transparent (or translucent) panel towards one side (but not shooting from the edge). By taking a more direct approach than traditional edge-lighting, they have cut out the losses that stem from the "edge interface" as well as achieving an incredibly thin package. When you have wavelenghts in nano-meters, you don't necessarly need millimeters to get photons bouncing around and jumping out where you want them to. Efficacies are on-par with other packaged devices, in that 100 lm/watt range, with the implication of that efficacy is the complete optical efficacy of a system implemented with their products, rather what would normally be prior to the panel or secondary optics, diffusers, etc. With the "glowing panel" luminaire looking positioned to catch traction for architectural lighting, I am expecting to see some interesting luminaire level action with their technology here in 2011.

Wrapping up the face-to-face updates, we had a chance to spend some time with Keith Ward, President of Luminus Devices. "The big chip technology is real," was Luminus' message, and there is no denying that they have demonstrated such in the projector space, with kilo-lumen implementations in the market today, and still brighter versions planned for show and tell at 2011 events. About half of their revenues come from the projection market (a healthy rebound from a company that suffered through the death of the DLP projection TVs at the hands the flat-panel revolution). The other half belongs to lighting, which includes some specialty markets, such as medical instrumentation (thank you for no heat in that beam which is finding its way into those parts of my body, thank you very much...), and entertainment, where small and bright have to team together, and 100 lm/watt efficiencies are just an added benefit that makes the choice simpler. Expect to see substantial results in 2011 in the outdoor markets, along with some totally new approaches that will move them rapidly forward in the kilo-lumen solutions sets.

A good year is in process, and based on the market opportunities, this is just the first of many. We'll have some of those market numbers dissected for you next time.