Scientists from Japan and Germany have devised a new, sustainable method for converting blue LED light into UVB.
The new system, which does not rely on toxic and inefficient materials traditionally used for UVB production, offers a more sustainable and environmentally friendly solution for UVB applications. The findings were published in the journal Angewandte Chemie.
Scientists have found that artificially produced UVB and UVC are useful in applications such as disinfection. UVB specifically has been applied in processes including photochemical reactions, detoxification of pollutants, and wastewater treatment. It is even used in the medical field in treatments for skin disorders such as eczema and vitiligo.
However, generating UVB currently requires sources such as mercury lamps, which are inefficient and toxic if improperly disposed of.
One way around this is to generate UVB by ‘upconverting’ the light produced by LEDs. Upconversion is a method in which a material absorbs two photons of light of lower energy and combines their energy to emit one photon of higher energy light. The method usually occurs using a series of organic materials.
Over the years, two research teams in Japan and Germany, led by Nobuhiro Yanai of Kyushu University’s Graduate School of Engineering and Christoph Kerzig of the Johannes Gutenberg University Mainz, respectively, have been working on evaluating various compounds for upconverting blue light from LEDs into UV light. Not only were they able to develop molecules that upconverted blue LED light into UVB, but they were also able to avoid the use of heavy metals that are traditionally used in such processes.
“Our investigations show evidence for a hitherto unreported blue-to-UVB upconversion that is also an avenue for safer and more sustainable production of UVB,” concludes Yanai. “However, this first upconversion system is liquid-based and relies on several bimolecular reactions that hamper its stability and long-term usage. Moreover, the current rate of conversion is around 1%, naturally, our next goal is to increase efficiency while developing reusable materials for versatile applications.”