(Invited) III-Nitride Ultraviolet LEDs and Lasers for Applications in Biology and Medicine

Solid-state ultraviolet (UV) light emitters are being developed for emerging biomedical applications such as surface sterilization, air/water purification, and medical treatments as a replacement for mercury vapor lamps. While these UV emitters offer many advantages over mercury lamps, such as more compact form factors, tunable emission wavelengths, and greatly increased lifetimes, they also suffer from a number of issues which hinder their implementation in many potential applications. UV emitters are based on AlGaN heterostructures which usually have very poor external quantum efficiencies (EQEs) of less than 10%, with EQEs decreasing with emission wavelength. This makes it very challenging to realize high efficiency UV emitters whose high energy photons are capable of inactivating viruses, bacteria, and other pathogens. This work discusses recent developments made by the Zhang Research Group at the Rochester Institute of Technology in improving the efficiencies of UV LEDs and lasers.