Someone was asking the other day what happened to the material that translucent have developed for LED's ? this bit below sounds very much like what Translucent have developed , unless someone has copied their IP or am I very mistaken?
Look at the gain in efficiency and also the reduction in costs, no wonder other companies are interested in the tech, I believe that it is Translucent technology, some may think differently? Make up your own minds here please, But I am excited as big Kev used to say!
This was a post by someone called Eavesdropper on the site below.
"The speed at which LED lumen output is increasing is staggering. Bridgelux has just released an LED with 135 lumen/W. They were able to get commercial grade performance from a silicon substrate LED for the first time in the industry. A single 1.5mm diameter LED operated at 350mA has output 135 lumens (4730K) at 2.9V. In the industry silicon carbide and sapphire substrates used to create epitaxial wafer, but the materials and process are expensive. Bridgelux went with low cost gallium nitride, grown, wafers from 150 - 300 mm diameters, with a 75% reduction in cost, in comparison.
The Bridgelux CEO, Bill Watkins, has this to say about the tech, "The significantly reduced cost-structures enabled by Silicon-based LED technology will continue to deliver dramatic reductions in the up-front capital investment required for solid state lighting. In as little as two to three years, even the most price-sensitive markets, such as commercial and office lighting, residential applications, and retrofit lamps will seamlessly and rapidly convert to solid state lighting.? ----------------------------------------------------------------
This is what Translucent say about their technology, It sounds very familiar if not exactly the same in my opinion?
http://www.translucentinc.com/GaN.html
Gallium Nitride on Silicon: vGaN?
machine Using cSOI? as a baseline platform, Translucent can eptiaxially grow using lattice matching and pre-stressing techniques single crystal GaN-on-Si device ready templates. The virtual GaN templates have been trademarked as vGaN? and are available upon enquiry. The vGaN? technology encompasses both an oxide insulator and a III-N layer. For example, photoluminescence mapping of the GaN layer using a commercially available mapper operating at 266nm with a 100mm diameter wafer exhibited excellent PL uniformities. These device-ready template wafers are now in a position to be supplied to producers manufacturers of Gallium Nitride device structures (i.e. LED and FET manufacturers). Translucent is now enabling device manufacturers designers to use proprietary processes whilst accessing the manufacturing benefits of Translucent?s scalable cSOI? technology platform with Gallium Nitride.
Current GaN-on-Si technology is very much focused on stress engineering. Successful approaches today use materials engineering to build in tensile stress at growing temperatures to compensate the compressive strain that develops on cooling. The Translucent rare earth oxide permits controlled, uniform and consistent stress engineering given the ability to blend different rare earth metal species in the single crystal oxide on the silicon substrate. Solid State Lighting (LEDs) using Translucent vGaN? technology
Today, virtually all of the commercially available LEDs produced using nitride semiconductors use sapphire as the starting substrate. This is becoming expensive and there are both technical challenges and cost penalties to increase the size of the wafer. Increasingly, the lighting industry is looking to adopt a silicon substrate solution. However, unlike sapphire wafers which are transparent, one of the key problems associated with using silicon is that silicon absorbs visible light and consequently LEDs produced on silicon automatically loose approximately half of their light output (LEDs emit in a lambertian pattern, i.e. equally in all directions).
Translucent has solved this issue very simply using a very high quality mirror called a Distributed Bragg Reflector (DBR). This is a lattice matched stack of materials all grown sequentially at Translucent with high and low refractive index. This patented mirror technology derived from the baseline cSOI? technology is called Mirrored Si?. The substrates with Mirrored Si? are designed using single crystal superlattices of REO and silicon, which because of the large refractive indices between the two materials, produce very efficient mirrors with peak reflectivities >90% at 500nm while delivering stop bands in excess of 100nm. Typical uniformities for these parameters are ~1%.
The rare earth oxide material developed by Translucent is the first material that is both single crystal and compatible with silicon and subsequent nitride epitaxy, from which a mirror like structure can be constructed. The vGaN? process is then used to transform the Mirrored Si? substrates into device-ready template wafers for LED epitaxy growth. The Mirrored Si? layers make the silicon surface highly reflective at typical LED emission wavelengths and eliminate the substrate loss.
SLX Price at posting:
$2.92 Sentiment: Buy Disclosure: Held
(20min delay)