# Looking for a source of LEDs with emission at 207 nm



## alternety (Mar 3, 2018)

I need to have radiation at 207 nm. I would like to use one or more LEDs. I have done a good bit of searching with little success. None of the words or numbers I have tried come up with anything but irrelevant junk. Does anyone know where such an LED might be found?

A filtered KrBr Excimer bulb would do it but I am looking for a hand held battery powered device with a reasonable (couple of hours or more) run time.

I have seen an approach using a 400 nm blue laser to hit a crystal to act as a frequency doubler to get 200 nm. But he crystal they use can't tolerate being exposed to, essentially, air. And there is a bunch of hardware to get things aligned and protected.


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## PhotonWrangler (Mar 4, 2018)

The shortest UVC LED wavelength I can find on Alibaba is 254nm. Are you working on that recent human-safe UV sterilization project?


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## alternety (Mar 21, 2018)

I am trying to; as an interested civilian. But I am real interested.

My 207 nm wavelength appears to have been superseded by 222 nm. I have found nothing in LEDs that hit that wavelength. Some esoteric (read hard and expensive) approaches exist. Taking a blue laser and hitting a crystal that acts as a frequency doubler can hit 222 nm on the nose.

I have a high probability of needing some significant surgery. After researching infection rates; I am not comforted. 10% overall, and of those seriously diminishing survival. I have been warned by a surgeon, success rate probably lower than that for my requirements. Biggest impact is hospital "improved" antibiotic immune pathogens. I can't control the operating theater, but the projected 5 - 7 days in the hospital are ripe for infection. Hence, I want to build one of the UVC devices. Preferably something along the lines of a flashlight. I can keep that in my room and clean up my person and personal space periodically. And, if the opportunity exists, I can use it at home. Flu and pretty much everything else is killed. Airborne and surface pathogens. Massively superior to the little alcohol squirters. Incredible business opportunities.

I have found a source that seems to work. It is a KrCl light source. With, I believe, a built in filter that gets rid of any spurious emissions. They have a development kit and a picture with little information. They are probably holding things close to the chest waiting to start selling systems when the FDA approves things (apparent estimate, 2+ years). Their power supply in the kit is of a size that may be workable with a single light source, some Li batteries, and maybe a different approach to generating the high voltage needed. One light source should be enough for my purpose. But they will not sell me a kit.

I appear to be at the end of my attempt. One company showed a large and clumsy line operated hand held sterilizer, but it did not appear to be for sale. Unlikely to be acceptable in my room.

It is unfortunate it takes so long for moving through the government process. This stuff is essentially magic. Old, but relevant, quote "Technology sufficiently advanced is indistinguishable from magic". It kills everything and harms no one. They could have a real opportunity to fast track the technology to save lives by eliminating infections and massively lower costs for treating infections that could be avoided. Billions$

Any suggestions welcomed.


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## PhotonWrangler (Mar 21, 2018)

You could always use the regular handheld fluorescent UVC lamps as long as you don't aim them at your eyes or skin. Not an idea situation but still better than nothing. Some of they are pretty in expensive. I have one that I use on my computer keyboard once in awhile.


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## HarryN (Mar 26, 2018)

Frequency doubling (and tripling) using crystals has been around for a long time. It isn't as efficient as direct emission, but gets you there when other options are difficult to purchase.

SETI (now part of seoul ) and Nitek have been historical technology leaders for UV leds, both off shoots of the work at University of South Carolina in Columbia. If they can't make it, it might not exist.

BTW - if you like red velvet cake, Columbia, SC is definitely a top location for finding it.


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