Researchers have engineered a system that transforms the blue light from LEDs into ultraviolet light. This advancement was disclosed by Kyushu University’s press office.
The Sun remains the primary source of ultraviolet radiation on Earth. UV light is categorized by wavelength into three classes: UV-A, UV-B, and UV-C. Only UV-A typically reaches the planet’s surface, while most UV-B and UV-C are blocked by the ozone layer. Yet, man-made UV-B and UV-C hold value for disinfection, driving photochemical reactions, breaking down pollutants, and wastewater treatment. They also play a role in treating certain skin conditions such as eczema and vitiligo. Mercury lamps have traditionally served these purposes, but they suffer from inefficiency and toxicity if not handled properly.
For years, Japanese researchers led by Nobuhiro Yanai and collaborators have explored substances and materials capable of absorbing pairs of blue-light photons and effectively combining them with twice the energy. This arises from a triple-energy interaction that enables the transformation. “The blue LED wavelength sits closest to ultraviolet light. We succeeded in converting longer-wavelength blue LED light into short-wavelength UV-A. Our next aim was to identify compounds that could convert blue LED light into UV-B,” the team notes.
In practical terms, this discovery points toward the possibility of a UV-B lamp. However, before such a lamp can be realized, the stability of the liquid working fluid must be addressed. The technology’s main advantages lie in its simplicity and its environmental friendliness, offering a potentially safer and more sustainable path to producing UV light compared with traditional mercury-based sources. The implications extend to disinfection, advanced photochemistry, and pollutant detoxification, with broad relevance for water treatment and public health. Researchers emphasize that further work is needed to ensure long-term stability, efficiency, and scalability for real-world use. This progress demonstrates how solid-state photonics can leverage existing blue-light sources to broaden access to ultraviolet radiation while reducing environmental impact. (Citation: Kyushu University press office)
Overall, the development represents a meaningful step in photonics, aiming to convert ubiquitous blue LED light into ultraviolet light through a straightforward, eco-conscious approach. The capability to iteratively tune the emitted UV wavelength by selecting appropriate absorber materials promises to open new avenues in sterilization, material processing, and medical therapies, with ongoing studies focusing on optimization and safety. As the technology matures, it could influence consumer lighting, industrial disinfection, and environmental remediation, potentially reshaping how ultraviolet light is generated in a safer, more sustainable way. (Citation: Kyushu University press office)