# How much more room for improvement is there with LEDs? Will they become much better?



## HighlanderNorth (Sep 18, 2011)

I'm new at LED technology, and this is only my 2nd post here, and I've probably got much to learn about this topic.

I'm embarrassed to say that I thought Maglights were the top-of-the-line as far as flashlight were concerned.....

I remember years ago seeing LED lights that were so dim that it was laughable.

But I've noticed in the reading that I've done that it seems the LEDs have really only gotten as good as they are now recently. Now I know that there is usually room for improvement with most technologies, but some technologies are at the end of their ropes as far as improvement is concerned. I would imagine that there isnt going to be much more improvement in incandescent bulbs for instance. 

The first decent quality LED type light source I bought was in 2007. I was looking for a backpacking type headlamp, and I discovered a flashlight review sight called flashlightreviews.com. I was also spending LOTS of time reviewing many other new items I needed to rebuild my backpacking/camping gear supply, which was completely outdated and old(1980's and 1990's). 

It seemed that the guy who runs the flashlightreview.com site was at least semi-retiring, and wasnt doing as many reviews, but there were some new ones at the time. I found a headlamp from an unknown company that was called the LED Duet. It had 3, 5mm Luxeon LEDs, and a larger, more powerful LED. The 3, 5mm Luxeons were lined up side by side, and the larger LED was above. There were 5 modes. You could turn on 1-2 or 3 5 mm LEDs at the same time, or just the larger one, which was much brighter and has much longer range. There is also a strobe feature. The headlamp also has a battery charge indicator LED that tells you if it has a low, medium or high charge. It runs on 3 AAA's. These features were the same as a much more expensive Princeton tech unit, which also had 5mm's and 1 larger LED, but ran on 4AAA's so it was brighter, but the LED Duet was certainly bright enough when used on a mountain trail late at night, or at the campsite. It has worked great, and has good battery life. It got 4 out of 5 stars on the review site.

But now, there are new companies making LEDs that seem to be more efficient than Luxeons, according to what I've seen on that review site. They have the same brightness, with twice the efficiency. 

But are the LED manufacturers getting close to reaching the zenith of this technology, or is there still a lot of room for further improvement in efficiency, power and brightness?

I am now seeing a lot of Cree LEDs being offered in lights. Are there other new or older companies that are producing top LEDs? 

Also, are American companies competitive in the LED market, or are we losing out there too? I hate to buy Chinese stuff.......To be honest.


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## mr.snakeman (Sep 18, 2011)

Just a quicky: you ain´t seen `nothin´yet. The advances in LED technology are moving so fast that it is almost impossible for a lay person to keep up with the advances that are being made on a daily basis. Good luck in your search.


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## JacobJones (Sep 18, 2011)

Luxeons are now outdated even though they where cutting edge a few years ago. The big three when it comes to LEDs are Cree, Seoul semiconducter and luminus devices. Cree is American and I believe they are leading the way in LED technology


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## dosei-45 (Sep 18, 2011)

I'm very much of the mindset/belief that we are just starting to scratch the surface of the LED's potential.


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## yowzer (Sep 18, 2011)

HighlanderNorth said:


> I'm embarrassed to say that I thought Maglights were the top-of-the-line as far as flashlight were concerned.....



No need to be embarrassed over that. Lots of people think the same, and if you're judging based on the lights that are available in typical retail stores in the US, it's only to be expected. And, reportedly, the newest Maglight models aren't that bad even by this place's standards.


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## JacobJones (Sep 18, 2011)

I also used to believe maglites where the best, and it's true they where... 30 years ago. I'm shocked how quickly led technology has advanced, 10 years ago LEDs wherent good for much more than indicator lights on computers and other electronic devices. I can't wait to see what LEDs are available in another ten years and I can look back at threads from now and think about how far we have come. hopefully I'll still have all my Cree XP-G lights then so I can see how dim and outdated they are. Even in the short time since I became a flashaholic just before last christmas LEDs have advanced, LEDs have become significantly more efficient in that short time with the release of the Cree XML


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## MikeAusC (Sep 18, 2011)

Cree currently state on their XM-L Datasheet "1000 lumens with 100 lumens per watt efficacy"

The theoretical limit for white phosphor-based LEDs is 300 lumens per watt. 

No doubt non-phosphor white LEDs will then start to break that barrier.


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## DM51 (Sep 18, 2011)

Welcome to CPF, HighlanderNorth. 

As your thread is about LED technology rather than LED Flashlights, I'm moving it to the LED section where these discussions are held. You'll find many other threads there about the new advances in LEDs, and I'm sure you'll find them interesting.


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## calipsoii (Sep 18, 2011)

JacobJones said:


> Luxeons are now outdated even though they where cutting edge a few years ago. The big three when it comes to LEDs are Cree, Seoul semiconducter and luminus devices. Cree is American and I believe they are leading the way in LED technology


 
Actually, while luxeon's haven't seen much use in recent flashlights, they are still hard at work creating high-quality LED's for the consumer lighting market. They now go by the company name LumiLed's and were bought by Phillips. They recently won the L-prize for their 60W lightbulb replacement. http://www.philipslumileds.com/L-Prize

And actually, the new 85CRI 4000K Rebel isn't such a slouch either. ZebraLight is using it in the SC51c.

Disclaimer: I don't work for them, but I disagree when people say they're done. They still put out a decent offering, they're just targetting a different market than Cree's "OMG EFFICIENT LUMENS" campaign.


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## HighlanderNorth (Sep 19, 2011)

JacobJones said:


> Luxeons are now outdated even though they where cutting edge a few years ago. The big three when it comes to LEDs are Cree, Seoul semiconducter and luminus devices. Cree is American and I believe they are leading the way in LED technology


 

**You stated that Cree is an American LED manufacturer, and is leading the way. But one more day has passed, so Cree has probably moved to China by now.

To DM51: Sorry about posting this thread in this forum area..... I was mainly interested in asking about LED technology advancement for flashlights, but I guess it is a question that applies to ALL LEDs, not just LEDs for flashlights.


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## Curt R (Sep 19, 2011)

The major LED flashlight manufacturers get to look at the latest in
LED technology before the rest of us. But sometimes they are the 
last to get to market. SF started working on their latest high power
flashlight 3 years ago using the Seoul P7 LED. I do not know if they
use the Cree MC-E or the P7, however when they brought it out several 
months ago, it was obsolete. And at $695.00 USD it cost more than
double that of a US built 800 Lumen light using the latest Cree XM-L.

As for Mag, they are also outdated with their newest LED lights. The big
US based companies are building for the consumer market and not to 
provide the latest technology to the uninformed. They design and 
manufacture to cost annalists. 

The next LED to come from Cree will be close to the Luminus SST-50 in
size and power at less that half the cost. Cree has test bench LEDs that
exceed 200 Lumens per watt. Getting that technology to manufacturing
is always the time and real cost stumbling block. You must also have a
market for technology verses what you are currently producing and the profit
margin difference. 

Our little world of flashlights is an afterthought and not a concern to the LED
manufacturers. We may think that a 100 million flashlights a year is a big
deal, but to them it is a very small percentage of their output.

Curt


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## JacobJones (Sep 20, 2011)

HighlanderNorth said:


> **You stated that Cree is an American LED manufacturer, and is leading the way. But one more day has passed, so Cree has probably moved to China by now.



Well they do have a factory in china making their LEDs aswell as in America, but they are an American company


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## LEDninja (Sep 20, 2011)

:welcome:


HighlanderNorth said:


> You stated that Cree is an American LED manufacturer, and is leading the way. But one more day has passed, so Cree has probably moved to China by now.


Cree makes the LED die (the part that actually makes light) in the US and assembles the whole LED (die + case + optics + wiring) in both the US and China. Because the most important part is not made in China the Chinese are unable to make illegal bootleg copies. (There are identical looking products but they do not perform as well.)

-

EDIT
The old Luxeon is about 30 lumens per watt.
The Cree XRE is about 80 lumens per watt (P4 bin) to 114 lumens per watt (R2 bin)
The Luxeon Rebel is 60-90 lumens per watt.
The Cree XPG is about 139 lumens per watt.
The Cree XML is about 160 lumens per watt.
As mentioned earlier:
Cree experimental 200 lumens per watt.
Theoretical limit for blue/phosphor LEDs 300 lumens per watt.
-
While RGB LEDs can go higher they only have red, green, blue. No orange, yellow, cyan, or violet. Not a problem in LED TVs and computer monitors but may be a problem elsewhere.


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## clint357 (Sep 22, 2011)

I think that the ability to handle high heat would also be a massive improvement. Just think of the flashlight you could make if the LED was able to reach 800 degrees F without any damage. The light could be pocket sized and throw out a couple thousand lumens.


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## mattheww50 (Sep 22, 2011)

The heat problem gets better as the luminous efficiency increase. The more out the LED photons you can get, the few that are left behind to become heat. So a very high efficiency LED will require substantially less heat sinking capacity than a lower efficiency device. This effect becomes quite dramatic as the luminous efficiency passes 50%.


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## DM51 (Sep 22, 2011)

clint357 said:


> I think that the ability to handle high heat would also be a massive improvement. Just think of the flashlight you could make if the LED was able to reach 800 degrees F without any damage.


That's unlikely to help very much unless there is a similar improvement in the ability of the batteries to handle the heat produced by the LED. The same goes for your hand, actually...


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## kingofwylietx (Sep 22, 2011)

DM51 said:


> That's unlikely to help very much unless there is a similar improvement in the ability of the batteries to handle the heat produced by the LED. The same goes for your hand, actually...


 
So, the most efficient LED is one that you can run at full power, without it producing any heat. Heat = inefficiency.

Is that a correct statement? 

I have 2 generations of an LED light. One is 2 years old and consumes 30 watts. It gets fairly warm and puts out decent light. The newer one, which just came out last week, consumes 30 watts but doesn't get quite as warm...uses the same exterior casing, and puts out 40% more lumens. 

To me, that is an improvement in efficiency. The exact same case/heatsink, more light output, less heat (so they are not pushing the LED's as hard).

So, in my mind, if an LED product produces heat: It can be made more efficient.


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## calipsoii (Sep 22, 2011)

kingofwylietx said:


> So, in my mind, if an LED product produces heat: It can be made more efficient.


 
Anything that electrons flow through will produce heat.

The limit to *white* LED efficiency is largely due to the phosphor. A blue photon pump is blasting away at yellow phosphor, which is absorbing the blue photons and releasing "white" ones instead. There is not a 1-to-1 ratio in this operation. This is why two LED's that are identical except for their phosphor can have different lumen ratings. A phosphor with a higher CRI output puts out fewer lumens that one with a lower CRI.

Your argument that heat = inefficiency is more appropriate when comparing the base photon pump (blue) without bringing phosphor into the equation. Unfortunately, blue LED light isn't very appealing, so at least for now, efficiency as it applies to flashlights is the sum of many parts.


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## Epsilon (Sep 25, 2011)

Curt R said:


> *The next LED to come from Cree will be close to the Luminus SST-50 in*
> *size and power at less that half the cost*. Cree has test bench LEDs that
> exceed 200 Lumens per watt. Getting that technology to manufacturing
> is always the time and real cost stumbling block. You must also have a
> ...


Do you have more info about this? Are there even SST90 sized leds on the schedule? And what is the ETA on these leds?

Can't wait


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## Vox Clamatis in Deserto (Sep 25, 2011)

> Anything that electrons flow through will produce heat.


 
Izzat so? Wouldn't superconductors be a counterexample to your sweeping claim? The electrons flow in Cooper pairs, right?


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## shao.fu.tzer (Sep 25, 2011)

Vox Clamatis in Deserto said:


> Izzat so? Wouldn't superconductors be a counterexample to your sweeping claim? The electrons flow in Cooper pairs, right?


 
You are wise, but for superconductors to work, they have to be at ridiculously cold temperatures anyway - correct?


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## Vox Clamatis in Deserto (Sep 25, 2011)

> You are wise, but for superconductors to work, they have to be at ridiculously cold temperatures anyway - correct?


 
Yes they would, at least as far as we know right now. And discussion of quantum effects here on a hobbyist flashlight forum is perhaps usually not a good idea. But, we were talking about theoretical limits to LED efficiency so I was questioning the blanket premise that current flow always implies ohmic heating.

Maybe those electrons travel on Cooper tires now that I think about it...


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## wrf (Sep 26, 2011)

This thread needs a skeptic. I'll volunteer.

I think the advent of the blue LED gave a boost to LED lighting similar to how the advent of jet engines gave a boost to air travel.

I think most of what we are seeing is the maturation of that technology and also the related phosphor methodologies. Given that, I expect advancements to level out. Sure, there will be lab examples that do wonderous things. But when I got off the plane last week, I was getting off a 737, not some supersonic wonder.

I grew up in the dark ages. The 5mm Panasonic red/yellow/green LEDs I mail ordered from the Digi-Key flyer (yes flyer, not thousand page catalog like today) would not overdrive at all. My first LED light lasted all of seven seconds.

It has been a very long wait for any meaningful advancement, which in this case was the blue LED. You just can't take these advancements for granted.



Vox Clamatis in Deserto said:


> [...]The electrons flow in Cooper pairs, right?


 
Dang, now I have to Google "Cooper pairs"!!!!


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## jtr1962 (Sep 26, 2011)

wrf said:


> This thread needs a skeptic. I'll volunteer.
> 
> I think the advent of the blue LED gave a boost to LED lighting similar to how the advent of jet engines gave a boost to air travel.
> 
> I think most of what we are seeing is the maturation of that technology and also the related phosphor methodologies. Given that, I expect advancements to level out. Sure, there will be lab examples that do wonderous things. But when I got off the plane last week, I was getting off a 737, not some supersonic wonder.


Yes, we're already seeing some leveling out in advancements. For example, we're never again going to see efficiency double practically overnight. I think we'll be on a long, fairly slow evolutionary path from this point onwards, where we might see gains of 10% or 15% a year, until we finally plateau for good near theoretical limits.

I'm not sure if the analogy with air travel is apt here. If one takes the speed of sound as a sort of limit then maybe. Jet engines did allow us to fly fairly close to the speed of sound and then progress, at least in regards to increasing speeds, stopped there. However, the speed of sound is more an _economic limit_ than a theoretical one. If we had some inexpensive energy source, I've little doubt we would be flying in hypersonic transports now on suborbital trajectories. LEDs on the other hand have no such barrier to improving all the way to their theoretical maximums. The only reason they won't is if we can't figure out how, or if the only available means to gain a few extra percent results in much higher costs.



> I grew up in the dark ages. The 5mm Panasonic red/yellow/green LEDs I mail ordered from the Digi-Key flyer (yes flyer, not thousand page catalog like today) would not overdrive at all. My first LED light lasted all of seven seconds.


I remember LEDs back in the "dark" ages. So-called "sunlight viewable" LEDs were actually a big deal when they first started appearing in the 1980s. I remember how I actually considered those 50 or 100 mcd LEDs really bright (they were compared to everything else available at the time).



> It has been a very long wait for any meaningful advancement, which in this case was the blue LED. You just can't take these advancements for granted.


I played with my first blue LED in the mid 1990s, and my first whites around 2000. My thoughts on the latter were one day these will take over the world. I knew that with anything electronic it's only a matter of time before we figure out how to tweak it to obtain maximum possible performance. We went from efficiencies under 1% to 60% with blue LEDs in about 15 years. I think we'll hit 90-95%, but it'll probably take another 15 years.


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## blasterman (Sep 27, 2011)

Using the jetliner analogy; while the typical cruising speed of airliners at altitude has stayed about the same for several decades, what has continued to improve at a regular pace is fuel efficiency and engine reliability.

In terms of LED technology we've continued to see an improvement in lowered forward voltages and improved thermal management even though absolute efficiency improvements are obviously dealing with diminishing returns. Also realize that there has to be economic incentive for companies like Cree, Phillips, etc. to keep dumping $$$ into R&D rather than the same investment being used to improve existing production efficiency. Righ now the gulf between hyper efficient LEDs and mass produced fixtures that can utilize them is as big as it's ever been. A 3-5% efficiency improvement won't sell any more reels, so it's often not worth pursuing.


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## SemiMan (Sep 27, 2011)

LEDninja said:


> :welcome:
> 
> Cree makes the LED die (the part that actually makes light) in the US and assembles the whole LED (die + case + optics + wiring) in both the US and China. Because the most important part is not made in China the Chinese are unable to make illegal bootleg copies. (There are identical looking products but they do not perform as well.)
> 
> ...


 

Rebel, is 110-120 lumens/watt, Rebel-ES, 120 -130+ lumens/watt.


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## cdrake261 (Sep 27, 2011)

blasterman said:


> Using the jetliner analogy; while the typical cruising speed of airliners at altitude has stayed about the same for several decades, what has continued to improve at a regular pace is fuel efficiency and engine reliability.
> 
> In terms of LED technology we've continued to see an improvement in lowered forward voltages and improved thermal management even though absolute efficiency improvements are obviously dealing with diminishing returns. Also realize that there has to be economic incentive for companies like Cree, Phillips, etc. to keep dumping $$$ into R&D rather than the same investment being used to improve existing production efficiency. Righ now the gulf between hyper efficient LEDs and mass produced fixtures that can utilize them is as big as it's ever been. A 3-5% efficiency improvement won't sell any more reels, so it's often not worth pursuing.


 
That's providing all the led manufactures do not complete for having the most efficient led... The "my products is better than your's" comes to mind here.


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## slebans (Sep 27, 2011)

jtr1962 said:


> Yes, we're already seeing some leveling out in advancements. For example, we're never again going to see efficiency double practically overnight. I think we'll be on a long, fairly slow evolutionary path from this point onwards, where we might see gains of 10% or 15% a year, until we finally plateau for good near theoretical limits.


 
From a luminaire/bulb standpoint, I believe we will see annual efficacy increases exceeding 20%. The 25-50% annual cost reductions of the LEDs themselves will allow the manufacturers to use more LEDs at lower power/higher efficacy levels. Integration of the various luminaire/bulb components and increasing power supply efficiencies will also aid in reducing costs.

Stephen Lebans


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## blasterman (Sep 27, 2011)

> That's providing all the led manufactures do not complete for having the most efficient led


 
They aren't competiting as much as people think.

LED makers make money selling large batches of LED's to fixture/bulb makers, with Cree being a rare exception in that they make some of their own fixtures. 

An LED that's 10% brighter than a competitor doesn't mean much if the competitor costs 40% less. Or 80% less in the case of Chinese knock-offs {sigh}


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## Kinnza (Sep 27, 2011)

LED's manufacturers huge effort to increase efficiency past of that alternative technologies now is ended. Once all main LED manufacturers have high power white LEDs achieving 150lm/W on operating conditions, we still continue seeing efficiency improvements, but gradual and progressive, until, luckily, reaching 250lm/W on 10 years. As higher the efficiency level, the smaller in percentage the new improvements.

Now the focus is on lowering manufacturing costs. Many are working on the migration to silicon substrate, which technology is very well developed for mass production, and allowing the use of larger wafers, a key to lowering costs. But LEDs grown on silicon have lower efficiency, at least for the moment. But if they cost 1/3 for 1000 lm, they finally will displace other more expensive technologies, despite an small lower efficiency.

For sure than a flashaholic prefer to pay 3x for best LED and get the best color quality, the longer runtime and easier thermal management. But LED manufacturers thinks on the big market, not on us.

So it is to expect a slower rate on efficiency improvement from now on, but prices dropping continuously for a given amount of lm. Once LEDs have the performance to compete effectively with other lighting alternatives, new manufacturers, especially asians, currently producing silicon semiconductors will join, production capacity will grow very fast and later prices with go down as consequence of effective competence, that until now has been relatively limited.


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## Vox Clamatis in Deserto (Sep 27, 2011)

> Using the jetliner analogy; while the typical cruising speed of airliners at altitude has stayed about the same for several decades, what has continued to improve at a regular pace is fuel efficiency and engine reliability.


 
Cruise speed for airliners has actually dropped in the past three decades from what I can see. Legacy long haul planes like the 707 and 747 typically cruised at .86 mach or faster. 'Newer' designs like the 767 dropped to .82 or slower. Airbuses are usually slower than comparable Boeings, you gotta watch out for those trailing edge bird strikes.

LED's are a game changing developing technology, like jet engines were when they were introduced to commercial aviation, eventually far more reliable and for some power ranges much more efficient than the earlier technology.

I would suggest an even closer analogy might be the transition from vacuum tubes (valves) to transistors in electronics. The heated filament active component is replaced by a more reliable and longer lasting solid state device.


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## Kinnza (Sep 27, 2011)

For those interested on projections of performance/price of LEDs, take a look on DOE page: http://www1.eere.energy.gov/buildings/ssl/information_resources.html, and specifically, at Technology Roadmaps.

Last projection I am aware of states

Efficacy (lm/W): Price ($/Klm) of coolwhite (4750-7050K, CRI 70-80) and warmwhite (2580-3710K, CRI80-90) (Klm=1000lm), OEM prices.

2010: 134lm/W:13 $/Klm (CW) 96lm/W:18 $/Klm (WW)

2012: 176:6 141:7.5

2015: 224:2 202:2.2

2020: 258:1 253:1


On the detailed roadmap, each topic able to be improved is analyzed in deep.


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## jd_oc (Sep 27, 2011)

Kinnza said:


> For those interested on projections of performance/price of LEDs, take a look on DOE page: http://www1.eere.energy.gov/buildings/ssl/information_resources.html, and specifically, at Technology Roadmaps.
> 
> Last projection I am aware of states
> 
> ...



If this is true, in 4 years we'll be able to have quad xpg-type led P60 drop in for $8 + electronics and reflector that produces 3000+ lumens. Count me in!


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