UVC LED

LED technology – Efficient and versatile light source. Light-emitting diodes (LEDs) are an integral part of modern lighting today. From household lamps and traffic signals to advanced design installations and industrial applications, LED technology has revolutionized the way we generate and use light. Modern LEDs have an energy efficiency of over 90%, which means that the majority of the energy supplied is converted into light rather than heat. The lifespan typically exceeds 10,000 hours, making them both an economically and environmentally sustainable solution.

Historically, the first LEDs were limited in both brightness and lifespan. They overheated easily and had a short working time. However, with technological advancements – especially the development of blue LEDs – it became possible to create white light by combining red, green, and blue. This milestone was reached by Shuji Nakamura, who paved the way for the wide adoption of LEDs in both commercial and industrial contexts.

The color of an LED is not determined by the plastic material around the diode, but by the energy released by the electrons in the semiconductor material. This makes it possible to design LEDs with precise wavelengths for specific purposes.

UVC LED – Technology for advanced disinfection

UVC LEDs emit light in the ultraviolet spectrum between 200–280 nm and are primarily used for disinfection and sterilization. Unlike visible LEDs (380–700 nm), UVC LEDs are technologically more complex and require advanced material technology and precise manufacturing.

Structure and function

UVC LEDs are made by growing semiconductor layers – typically aluminum gallium nitride – on a substrate of sapphire. These layers can be up to 1200 in number and are doped with elements such as silicon and magnesium to control electrical conductivity. The active zone, called the quantum well, is where electrons and holes recombine and emit UVC photons.

Effectiveness depends on:

  • Material quality and crystal structure
  • Doping of p- and n-layers
  • The ability to extract photons without absorption in their own layers
  • Thermal management and packaging

Challenges of UVC LED technology

UVC LEDs are significantly more challenging to produce than traditional LEDs:

  • Material complexity: Aluminum gallium nitride is difficult to grow without defects.
  • Light extraction: UVC photons are easily absorbed by materials, reducing efficiency.
  • Doping problems: P-type doping is ineffective, which limits light production.
  • Heat generation: UVC LEDs generate significant heat, which requires advanced cooling and thermal design.
  • Material degradation: UVC photons have high energy and can damage the LED’s own structures.

Design demands

  • PCB (printed circuit board): Must be able to handle both power supply and efficient heat dissipation. Copper or ceramic substrates are typically necessary.
  • Optics: Lenses must be made of UVC-transparent and durable materials such as quartz or special glass. Ordinary plastic lenses degrade quickly and block UVC light.