Research from North Carolina State University will allow the development of energy-efficient LED devices that use ultraviolet (UV) light to kill bacteria and viruses. The technology has a wide array of applications ranging from drinking-water treatment to sterilizing surgical tools.
UV treatment utilizing LEDs would be more cost-effective, energy efficient and longer lasting, says Dr. Ramón Collazo, an assistant professor of materials science and engineering at NC State and lead author of a paper describing the research. Our work would also allow for the development of robust and portable water-treatment technologies for use in developing countries.
LEDs utilize aluminum nitride (AlN) as a semiconductor, because the material can handle a lot of power and create light in a wide spectrum of colors, particularly in the UV range. However, technologies that use AlN LEDs to create UV light have been severely limited because the substrates that served as the foundation for these semiconductors absorbed wavelengths of UV light that are crucial to applications in sterilization and water treatment technologies.
A team of researchers from North Carolina and Japan has developed a solution to the problem. Using computer simulation, they determined that trace carbon atoms in the crystalline structure of the AlN substrate were responsible for absorbing most of the relevant UV light. By eliminating the carbon in the substrate, the team was able to significantly improve the amount of UV light that can pass through the substrate at the desired wavelengths.
Once we identified the problem, it was relatively easy and inexpensive to address, says Dr. Zlatko Sitar, the Kobe Steel Distinguished Professor of Materials Science and Engineering at NC State and co-author of the paper.
Commercial technologies incorporating this research are currently being developed by HexaTech Inc., a spin-off company from NC State.
This is a problem thats been around for more than 30 years, and we were able to solve it by integrating advanced computation, materials synthesis and characterization, says Dr. Doug Irving, assistant professor of materials science and engineering at NC State and co-author of the paper. I think well see more work in this vein as the Materials Genome Initiative moves forward, and that this approach will accelerate the development of new materials and related technologies.
The paper, On the origin of the 265 nm absorption band in AlN bulk crystals, is published online in Applied Physics Letters. Co-authors include Benjamin Gaddy, Zachary Bryan, Ronny Kirste and Marc Hoffman from NC State, as well as researchers from HexaTech Inc., Tokyo University of Agriculture and Technology, and the Tokuyama Corporation. The research was supported with funding from the U.S. Department of Defense.
Reference: Callazo R, et al. On the origin of the 265 nm absorption band in AlN bulk crystals. May 2012, Applied Physics Letters.
Â
Endoscopes and Lumened Instruments: New Studies Highlight Persistent Contamination Risks
May 7th 2025Two new studies reveal troubling contamination in both new endoscopes and cleaned lumened surgical instruments, challenging the reliability of current reprocessing practices and manufacturer guidelines.
Happy Hand Hygiene Day! Rethinking Glove Use for Safer, Cleaner, and More Ethical Health Care
May 5th 2025Despite their protective role, gloves are often misused in health care settings—undermining hand hygiene, risking patient safety, and worsening environmental impact. Alexandra Peters, PhD, points out that this misuse deserves urgent attention, especially today, World Hand Hygiene Day.
From the Derby to the Decontam Room: Leadership Lessons for Sterile Processing
April 27th 2025Elizabeth (Betty) Casey, MSN, RN, CNOR, CRCST, CHL, is the SVP of Operations and Chief Nursing Officer at Surgical Solutions in Overland, Kansas. This SPD leader reframes preparation, unpredictability, and teamwork by comparing surgical services to the Kentucky Derby to reenergize sterile processing professionals and inspire systemic change.