Handheld UV Light For Killing COVID-19 Enabled With New Transparent Conductor

A personal, handheld device emitting high-intensity ultraviolet light to disinfect areas by killing the novel coronavirus is now feasible, according to researchers at Penn State, the University of Minnesota and two Japanese universities.

Finding a new material with the right composition is key to advancing UV LED performance. The Penn State team, in collaboration with materials theorists from the University of Minnesota, recognized early on that the solution for the problem might be found in a recently discovered new class of transparent conductors. When theoretical predictions pointed to the material strontium niobate, the researchers reached out to their Japanese collaborators to obtain strontium niobate films and immediately tested their performance as UV transparent conductors. While these films held the promise of the theoretical predictions, the researchers needed a deposition method to integrate these films in a scalable way.

Nature – SrNbO3 as a transparent conductor in the visible and ultraviolet spectra

There are two commonly employed methods to sanitize and disinfect areas from bacteria and viruses — chemicals or ultraviolet radiation exposure. The UV radiation is in the 200 to 300 nanometer range and known to destroy the virus, making the virus incapable of reproducing and infecting. Widespread adoption of this efficient UV approach is much in demand during the current pandemic, but it requires UV radiation sources that emit sufficiently high doses of UV light. While devices with these high doses currently exist, the UV radiation source is typically an expensive mercury-containing gas discharge lamp, which requires high power, has a relatively short lifetime, and is bulky.

The solution is to develop high-performance, UV light emitting diodes, which would be far more portable, long-lasting, energy-efficient and environmentally benign. While these LEDs exist, applying a current to them for light emission is complicated by the fact that the electrode material also has to be transparent to UV light.

“You have to ensure a sufficient UV light dose to kill all the viruses,” said Roman Engel-Herbert, Penn State associate professor of materials science, physics and chemistry. “This means you need a high-performance UV LED emitting a high intensity of UV light, which is currently limited by the transparent electrode material being used.”

The rare combination of high transmission and high conductivity of SrNbO3 facilitates the improvement of existing UV LEDs suffering from poor EQEs, enabling energy efficient, long lasting, high performance, portable and environmentally benign solid state lighting solutions for UV sanitation, biomolecule sensing, UV phototherapy, UV curing, UV photolithography and high sensitivity solar blind detector technology.


Few materials have been identified as high-performance transparent conductors in the visible
regime (400–700 nm). Even fewer conductors are known to be transparent in ultraviolet
(UV) spectrum, especially at wavelengths below 320 nm. Doped wide-bandgap semiconductors employed currently as UV transparent conductors have insufficient electrical
conductivities, posing a significant challenge for achieving low resistance electrodes. Here,
we propose SrNbO3 as an alternative transparent conductor material with excellent performance not only in the visible, but also in the UV spectrum. The high transparency to UV light
originates from energetic isolation of the conduction band, which shifts the absorption edge
into the UV regime. The standard figure of merit measured for SrNbO3 in the UV spectral
range of 260–320 nm is on par with indium tin oxide in the visible, making SrNbO3 an ideal
electrode material in high-performance UV light emitting diodes relevant in sanitation
application, food packaging, UV photochemotherapy, and biomolecule sensing.

SOURCES – Penn State, Nature Physics Communication

16 thoughts on “Handheld UV Light For Killing COVID-19 Enabled With New Transparent Conductor”

  1. Never noticed anyone push back when called on not washing their hands. But yes I’ve noticed people not doing so.

    At least one strategy that I’ve seen Chinese buildings use is to put the wash basins outside in full public view.
    — Basic queue theory says you get better resource usage if both men’s and women’s toilets are using the same basins. So you need less basins.
    — Anyone who doesn’t wash does so in full public view, so is more likely to be shamed into doing the right thing.

  2. Yeah, we needed to bring up the discussion of societal practices of hygiene and disease prevention. Because washing your hands and face masks do prevent disease transmission and we will need to use them as a group again, when another new virus rears its ugly head in the near future.

    Something which will be probably more frequent, due to the number of humans now living and cavorting in virus infested places which were previously out of reach.

    As a more anecdotal aside, I’ve noticed some growing relaxation in Westerner’s public mores and habits related to personal hygiene (e.g. when and how often wash your hands, or take a bath), probably due to the belief that we were mostly safe from anything.

    At least I have noticed more people not washing their hands after going to the restrooms, taking offense if you remark it and even openly arguing against common hygiene practices as “bad”.

  3. Indeed, probably even slightly lower, given the gross under-counting of cases due to the abundance of asymptomatic but contagious ones, and the severe lack of test coverage in most countries.

    In many places it ought to start declining in prevalence and deaths soon, as the virus has already been spreading like wild fire there in the past months, and the surviving population will achieve herd immunity.

    In fact, we may already be seeing it in Italy, New York and other strongly afflicted places.

    After that, the populations will cease being so susceptible to it, and it will again be a very marginal flu like virus.

    But alas, it still has to run its course if many other places, like in Latin America and Africa.

  4. Vaping might actually save lives! I’m so sick of those “Truth” ads, they’re so tendentious. Then you find out the org is actually funded by the cigarette manufacturers, which explains why they focus like a laser on vaping.

  5. I’ve long noticed how people who have lived in places like China have habits that seem borderline OCD compared to my culture.
    That’s not really the case any more.

    I see that Jean has been voted down twice. Probably by microbes.

  6. Lots and LOTS of websites telling you what to put inside you, but this is the wrong part of the internet.

  7. To be clear, you can certainly get UV LEDs that can kill the virus, they’re a stock item.

    What this would enable is LEDs that produce UV in the range around 204nm which is relatively safe for human exposure, because it can’t penetrate skin or tear films. So you don’t have to take any special precautions using it to sterilize objects.

  8. The article is making it sound like deep UV LEDs are non existent. Right now, deep UV LEDs and laser diodes are quickly and cheaply taking the place of ‘macro’ lasers in many applications. If you just need a little light at those wavelengths, and things like coherence length, linewidth, beam mode, peak power and other parameters don’t factor, then a cheap light source will suffice. Many of the existing laser companies that specialized in building the larger, more intricate and expensive lasers are now getting their rear ends handed to them by these cheap replacements.

  9. All viruses and bacteria. If it’s got DNA, it won’t be able to replicate when it’s damaged.

  10. Question: is the effect limited to SARS COVID, all respiratory viruses or will it be a generic disinfecting tool for viruses in general?

  11. One thing that SAS-COV-2 managed to do, is turn us into germophobes.

    Which is good, we had become very relaxed about infectious diseases, thinking we had a remedy for anything.

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