For the past decade or so Dr. David Brenner from Columbia University has been leading the charge in research and development of a new wavelength of ultraviolet light that is more effective at inactivating viruses than standard UVC, AND also comes with the added benefit of it NOT BEING HARMFUL to humans and building occupants. The ability to disinfect the air and surfaces of buildings, while spaces are occupied, is a huge breakthrough in the scientific, lighting, and building science communities.
The below video is a presentation from Boeing / Far UVC Technologies, as they present their case on far-uvc to the Defense Systems Information Analysis Center (DSIAC). This is the most comprehensive presentation on Far-UVC technologies that I can find.
As we see larger adoption of Far-UVC technology and products, we will see a cost decrease overtime due to economies of scale. Currently excimer lamps are only manufactured by 2 companies worldwide and production has yet to scale. We believe over the next 5 years you will see a major transformation in the UVC space replacing low pressure mercury vapor lamps with excimer lamps or other light sources that produce light at the 222nm wavelength.