# Deep UV (254nm) LEDs



## thomaspf (May 21, 2007)

My first post here.

I have been looking to buy a deep UV LED but all I found were really expensive ($270/led) emitters from Seoul

http://www.biouvled.com/_homepage/home_kor/asp/main.asp

Are there any cheaper sources for 254nm leds?

Cheers

Thomas


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## DM51 (May 22, 2007)

Bump - for an interesting question. Most of the ones used here in mods etc seem to be longer wavelength, ~400 nm. The ones you mention above seem to be very specialised ones for scientific / medical etc purposes, and probably have to be very precise, hence the high cost. 

What do you want to use these for? 

And welcome to CPF!


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## wykeite (May 22, 2007)

http://www.roithner-laser.at/


Seem to have quite a few at reasonable prices.


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## Theatre Booth Guy (May 22, 2007)

Several months ago, I spoke to Curt at Peak LED Solutions looking for something similar. He said that they have and could again, make a UV light with a shorter wavelength. However, at that time, he said the UV led's were even more expensive (I passed and am waiting for better prices).


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## daywalker (May 22, 2007)

Hi Thomas,
you have just missed a groupbuy for those LED's here: https://www.candlepowerforums.com/threads/164603

Maybe you can try to ask per PM if there are any more leftovers.


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## Ken_McE (May 30, 2007)

https://designingin.com/ 350 and 360 nm FoxGroup LEDs. 350's cost way more than 360's. You have to register (free) to get prices.


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## thomaspf (Jun 3, 2007)

Thanks for the replies. It looks like no one has a cheaper source for these 254nm LED.'s.

I wanted to build a small flashlight to look at flourescence in minerals and the longer wavelength UV leds do not work for these minerals.

For the time being I will probably go with a standard portable UV light which can be had for about $50.

Cheers

Thomas


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## Lunal_Tic (Jun 3, 2007)

thomaspf said:


> Thanks for the replies. It looks like no one has a cheaper source for these 254nm LED.'s.
> 
> I wanted to build a small flashlight to look at flourescence in minerals and the longer wavelength UV leds do not work for these minerals.
> 
> ...



Just curious, what minerals won't fluoresce under a 365nm UV light?

-LT


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## PhotonWrangler (Jun 3, 2007)

The most spectacular ones - including Franklinite and Willemite.


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## Bullzeyebill (Jun 3, 2007)

What is the nm of the plain old black lights.

Bill


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## PhotonWrangler (Jun 3, 2007)

Bullzeyebill said:


> What is the nm of the plain old black lights.
> 
> Bill



Those are 365nm. The Fox Group LEDs come in at 360nm, actually a tad shorter than traditional fluorescent black lights, but as LED wavelengths get shorter, their output gets weaker.


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## Lunal_Tic (Jun 3, 2007)

I thought that glass or plastic stopped the really short UV. How could you make an LED that actually got the UV past the "plastic" package or lens?

-LT


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## thomaspf (Jun 3, 2007)

On a recent geology trip my son collected some interesting minerals. I forgot the names but I do recall that some of them contain Strontium which was bright green under these 254nm lamps and they glowed on after turning off the light. We also collected some bright orange and blue stuff. 

I have a 360nm UV led and these minerals just don't do anything with that light.

Thanks

Thomas


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## Lunal_Tic (Jun 3, 2007)

Isn't Strontium what they put in glow powder and the hands of watches?

-LT


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## Alteran (Jun 3, 2007)

Tritium is used in some watches. I suppose the sun would give off the proper wavelength UV, but of course, it would be drowned out in the day. It would have to be absorbed then, and still be seen later on.


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## PhotonWrangler (Jun 3, 2007)

Lunal_Tic said:


> I thought that glass or plastic stopped the really short UV. How could you make an LED that actually got the UV past the "plastic" package or lens?
> 
> -LT



They use quartz instead of regular glass. That's the main reason why shortwave fluorescent lamps cost more than LW bulbs.


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## Lunal_Tic (Jun 3, 2007)

A quartz encased LED, that sounds cool. I wonder if a quartz lens would be better than the sapphire that I've got on a 365nm now. I know it blocks a bit of output. I had a hard time finding a high output 365nm, 254nm is going to be tough methinks.

-LT


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## optolite (Jun 4, 2007)

The only 254nm LEDs that I know of are the SET ones and as it has been said before they are are too expensive for commercial use. This is because going lower in wavelength is a mix of art and science, there are many factors to consider for manufacturers and it takes more time to develop UV led technology than visible LED technology. Prices do get sort of ridiculous when you go in the UV-B and UV-C range but this is because the technology is just prevailing. I remember the first computer that i bought cost me about 5000$ and well compared to now, in terms of price and performance i would not pay a penny to have one. Expect the same in UV LED technology, its only a matter of time til we have a low wavelength UV LED source that wont cost an arm and a leg.
Cheers


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## optolite (Jun 4, 2007)

As for fox Group LEDs theyr typical output is 361 - 362 nm at 20mA, you can get the specific 365nm peak at a higher forward current(wont damage if you want to pulse the LED), or even after keeping the leds on for a couple of minutes( heat shifts the spectrum a little )


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## Linda Tan (Apr 28, 2016)

thomaspf said:


> Thanks for the replies. It looks like no one has a cheaper source for these 254nm LED.'s.
> 
> I wanted to build a small flashlight to look at flourescence in minerals and the longer wavelength UV leds do not work for these minerals.
> 
> ...


hello Thomas, since it's a long time of you publish your question.
I think you should already know that now have a alternatives for 254nm led, that is $275nm uvc diode:www.sfleds.com
it's cheap and similar function as 254nm.


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## Boosted98gsx (Dec 25, 2018)

Sorry to thread necromance here, but it's been a few years since the OP and wondering if tech has advanced to make these more affordable yet? Also looking for 254nm diodes for mineral detection.

Thanks!


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## WalkIntoTheLight (Dec 26, 2018)

Wow, a UV-C LED emitter? I didn't even think they made those in an LED source. Very cool. Dangerous! But still cool. Mmmm... I love the smell of ozone in the morning.


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## Thetasigma (Dec 26, 2018)

365nm is fairly common these days and available in a few production lights, but that is a higher wavelength and pretty much all UV-A


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## PhotonWrangler (Jan 8, 2019)

Just ordered a couple of ~280nm LEDs to try out as mineral lights. They're fairly low power but the manufacturer claims that they can be used for sterilization. They're probably not as effective as the classic UVC 254nm wavelength, but it will be interesting to see what they can do for my fluorescent mineral hobby. Maybe I'll have germ-free minerals.


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## MTRun! (Apr 29, 2019)

I hear you, I still cannot find a solid 254nm LED. Thanks for the updates PhotonWrangler. There is a vendor on eBay drop shipping a 265nm MCPCB for $40 from a company called UVTaoYuan. Thorlabs has a low power MCPCB at 265nm for over a thousand dollars (yes $1K) and a slightly more affordable 275nm MCPCB for $231; part numbers M265D2 and M275D2 respectively. The 275nm board from Thorlabs is tempting to try, but not cheap.


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## PhotonWrangler (Apr 29, 2019)

Gah. At those prices I'd be pretty worried about powering them up for the first time. I'd want a slow-start circuit for sure.


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