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Considering buying UV-C LED lamps from China for germicidal disinfection?

Considering buying UV-C LED lamps from China for germicidal disinfection?

Posted by Marinebeam on 30th Jul 2020

DON'T!

With the current Corona virus issues, we get many questions about using LEDs with an ultraviolet (UV-C) wavelength for killing bacteria, and more specifically viruses like Covid 19.  

While UV-C light is very effective at eradicating pathogens, there are huge technical issues related to producing low-cost short-wavelength UV-C LEDs with a high enough power conversion efficiency necessary to have a good germicidal efficacy.

Why?  Blue and ultraviolet LEDs use a Gallium Nitride (GaN) base. The trouble is that GaN is is not transparent to UV-C light.  The result is that even in the best examples of UV-C LEDs, the photon extraction efficiency is less than 5%, so the power conversion efficiency is horrible.  Other coatings and silicones used in LED manufacturing to protect the LED die also absorb UV-C wavelengths, compounding the issues and the price.

UV-C LEDs are very expensive, and still very inefficient, but many companies and labs around the world are working on this problem.  Currently, low-pressure mercury vapor lamps provide a more effective solution than LEDs.

The bottom line is that you aren't going to purchase a cheap and effective UV-C LED germicidal lamp or wand from Amazon, or any of the Chinese internet sites.   Chances are you will receive a nice purple blacklight, which will work great on your old psychedelic glow-in-the-dark posters, but be pretty useless against Covid 19.