UVCLEDs

UVC LEDs are ultraviolet LEDs designed to emit in the UVC portion of the spectrum, roughly 100 to 280 nanometers. Commercial devices commonly emit around 260 to 280 nm, with some research devices operating toward shorter wavelengths. They rely on III-nitride semiconductor technology, typically aluminum gallium nitride (AlGaN) active regions on sapphire or silicon carbide substrates.

Operation and design: When forward biased, electron-hole recombination in the AlGaN active region releases photons in the UVC range. Device efficiency is affected by factors such as material defects, non-radiative losses, and the high aluminum content required for deep-UV emission. Modern UVC LEDs are produced in compact packages with UV-transparent optics and thermal management to cope with heat and light extraction limitations.

Applications: UVC LEDs are used for disinfection and sterilization of air, water, and surfaces, in healthcare facilities, laboratories, consumer water purifiers, portable sterilizers, and industrial processing lines. They offer advantages over traditional mercury lamps, including fast switching, compact form factors, and absence of mercury.

Safety and limitations: Direct exposure to UVC light can damage skin and eyes; devices are used in closed or shielded systems with safety interlocks. UV exposure can also degrade some polymers and coatings. Current UVC LEDs generally have lower radiant power and shorter lifetimes than conventional UV lamps, and higher costs; production is advancing but widespread adoption in some sectors remains limited by efficiency and price.

Outlook: Ongoing improvements in epitaxy, surface passivation, and packaging are expected to raise efficiency and output, expanding applications in sanitation and sterilization, consumer devices, and water treatment. Research also explores a range of wavelengths and materials to balance safety, efficacy, and availability.