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| | Seoul Semiconductor claims 5x lumen density with non-polar LEDs (Updated) | | 13 Jul 2012 | | Seoul Semiconductor has announced that it will introduce LEDs based on non-polar technology, which it claims will deliver over 5x the lumens per unit area of conventional LEDs. | | Seoul Semiconductor, an LED manufacturer based in Seoul, Korea, has unveiled a new LED product based on non-polar gallium nitride (GaN) technology, which it states "will deliver 5x the brightness per unit area of die than conventional LEDs by driving the LEDs at higher current densities." At the same time, the University of California (UC) in Santa Barbara has received a $500,000 endowment from Seoul Optodevice Company and James Speck has been named the campus's first Seoul Optodevice Chair in Solid State Lighting.
Non-polar GaN
Non-polar technology involves the utilization of the one of the non-polar planes in the GaN crystal, either the a-plane or m-plane, whereas traditional LEDs currently utilize the polar c-plane. Non-polar LEDs offer the potential of reduced electrical resistance, increased electrical efficiency, reduction in color shifting with varying operating current, and smaller device size.
Seoul Semiconductor’s patented nPola approach has been under development for over 10 years. According to the company, the lumen density of its LEDs has been dramatically improved by 5x over the conventional LED based on equivalent die surface area and it expects to further improve this margin to 10x with future implementations.
With this approach, Seoul Semiconductor claims that fewer LEDs are needed to achieve a given light output per replacement bulb. For example, in a 60W-equivalent LED lamp, generally 10-20 LED packages are used, but with the nPola product, the same light output could be achieved using 1-2 packages. Seoul also claims that while the luminous flux of a power chip LED in mass production is approximately 100 lm (warm white) today, this new product could produce 500 lm by driving the LED at higher current densities.
Seoul Semiconductor CEO, Chung Hoon Lee, expressed strong confidence in the new product by saying "I've worked very hard for the past 20 years in this industry and it is safe to say that this new product is the culmination of 20 years of core technologies development. It is a major milestone for the LED light source."
UC Santa Barbara receives $500,000 for Endowed Chair
UC Santa Barbara's Solid State Lighting & Energy Center (SSLEC), a provider of leading-edge research in energy-efficient lighting, power electronics, and solar energy technology, has received a $500,000 endowment from Seoul Optodevice Company to further its research on GaN for use in electronics and solid-state lighting (SSL).
James Speck, a professor of materials at UCSB, member of SSLEC's Executive Committee, and director of the Interdisciplinary Center for Wide Band-Gap Semiconductors, has been named the campus's first Seoul Optodevice Chair in Solid State Lighting.
"Mr. Chung Hoon Lee and the Seoul Optodevice Company are leaders in the field, and have been longstanding supporters of UC Santa Barbara's Solid State Lighting and Energy Center, which is advancing the frontiers of research in energy-efficient solid-state lighting, and helping to create a more sustainable future for us all," said Chancellor Henry Yang. "We are deeply grateful for their vision and generosity in establishing the Seoul Optodevice Chair in Solid State Lighting, and we are very proud that Professor Jim Speck will be the inaugural chair holder."
"This endowment by Seoul Optodevice Company is critically important because our research in gallium nitride semiconductors places the college at the forefront of energy efficiency technology," said Rod Alferness, dean of the College of Engineering. "Professor Speck is leading this charge and understands how our relationship with industry is a driving force behind discoveries in solid state lighting."
Speck's research focuses on the relationship between thin-film electronic materials growth, and microstructure, as well as the link between microstructure and physical properties. In 2010, he received the IEEE Photonics Society Aron Kressel Award for his work on nonpolar and semipolar GaN-based materials and devices.
| | About the Author | | Laura Peters is the Senior Technical Editor of LEDs Magazine. | | COMMENTS | | Name: wrong theory? Posted: Thu, 12 Jul 2012 07:07 |
| It is pity that this uninformative press release is released. SSC is telling in the release that present LEDs can produce light 100 lm/W and this new one is producing 500 lm/W. Right???
This makes me think that there is something wrong because theorethical maximum for the some how white looking light (RGB) is, as far as I know, 400 lm/W. In this (RGB) case the CRI is poor because there is only three spectral peaks in the spectrum. If all visual spectrum wavelenghts is even but nothing else is produced then the theorethical maximum is less than 200 lm/W.
So I would believe 200 lm/W and maybe 300 lm/W with very poor CRI but 500 lm/W is telling me something else...
Sure they are invented something but what and how good it is? I don't know. | | Name: theory okay. Posted: Thu, 12 Jul 2012 18:07 |
| They aren't claiming 500 lm/W. The improvement is 5x the brightness at the same surface area. They are still running the same total power through the chip, but instead of dividing it over multiple die they are running the nPola die at a much higher current density. As a result they can use fewer die greatly reducing the epi cost (assuming similar structure and substrate cost) and reducing the packaging cost by reducing the number of total die used. | | Name: cliff Posted: Thu, 12 Jul 2012 22:07 |
| What they're claiming is not 5x efficacy, but 5x lumen density. So if previously you needed 2.5mm^2 surface area to produce certain brightness, with their technology you only need 0.5mm^2
Whether that's true and where they got their numbers is questionable, however. They claim that current power LEDs normally go up to 100lm... Meanwhile, currently, the XM-L for example can go up to almost 10x that! Administrators Reply You are correct, and we have updated the article upon clarification with Seoul Semiconductor. The efficacy is not higher, it is the lumen density delivered by the LEDs. Seoul has not revealed specific LED performance numbers but has said they will be revealed in the next several weeks. | | Name: mikpower Posted: Fri, 13 Jul 2012 01:07 |
| There was no mentioning about lm/W in the press. It's Lumen per LED would be 5X. So actually the Lumen intensity in space would be 5X. One of this new LED probably consumes the same amount of power as 10-20 traditional LEDs, if not more. I suspect because of the increase in lumen and heat intensity, the die temperature increases therefore lm/W probably will be lower. | | Name: wrong numbers... Posted: Fri, 13 Jul 2012 12:07 |
| Just to answer quickly to the published comment at the end of the article. The author believes that the non polar LED efficiency is expected to be 500 lm / W. However, in the taxt, it is pointed out that the luminous flux is increasing from 100 lm to 500 lm, it does not concern the efficiency. As a matter of fact, nothing is said concerning the operating electrical power used to achieve this luminous flux... which, by the way, would be very interesting to know ! | | Name: avrcrao Posted: Sun, 15 Jul 2012 06:07 |
| What about the temperature rise and its effect on life? | | Name: billy leaves-led-lighting Posted: Thu, 22 Nov 2012 01:11 |
| There is no update on the nPola in the past four months.
Does it mean that the concerns from earlier comments are real:
luminous efficacy is not good,
heating due to high current density is not helpful,
and no further improvement is reported yet?
| | Name: bbb71 Posted: Wed, 06 Feb 2013 10:02 |
| I have seen presentation with some details about nPola. Applications for this product are those, where lm/cm2 is the most important factor, not lm/w or lm/$. There are some improvements in R&D, but the overall reliability should remain at the similar level as for high-power LEDs (with traditional sapphire and SiC3 substrates). Obviously package is one of the biggest challenge in this field, but as far as I know, is being developed now with nice performance. This company is doing really well with this product, it may be another big step in this industry, like Acrich2 technology is at the moment. I would never except from this korean company to do such progress! |
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