Solid-state material converts sunlight into UV light
Scientists have developed a solid-state material that can convert sunlight into ultraviolet (UV) light, potentially enabling new applications in disinfection, medical treatments, and environmental monitoring without needing electrical power. The material absorbs visible light and re-emits it as UV light, offering an efficient and sustainable way to generate UV radiation directly from sunlight.
Background
A team of researchers has developed a solid-state material that absorbs ordinary sunlight and re-emits it as ultraviolet (UV) light. This matters because UV light is used for sterilization (water/air/surface disinfection), curing industrial adhesives and coatings, and some medical treatments — but producing it efficiently typically requires electricity (via UV lamps or LEDs) or toxic mercury-vapor bulbs. If this new material works at scale, it could enable passive, energy-free UV generation from sunlight alone. The advance is in a class of materials called "photon upconverters": they combine the energy from two low-energy photons (from sunlight) to produce one higher-energy photon (UV). Historically, efficient upconversion required intense laser light and organic solvents; making it work in a solid material under normal sunlight is the breakthrough reported here.