Linköpings universitet


To date, the most promising technology for illumination market to replace conventional lightning sources is white Light Emitting Diodes (LEDs). However, this technology is in an initial stage towards commercialization for general illumination market and the production of conventional white LEDs is highly energy consuming and employs hazardous chemicals for humans and the environment.

In order to bring white LEDs to the general illumination market there is a need for development of innovative white LED technology leading to improved device functionalities as white light with high energy efficiency, high color quality independent of operating time, temperature, viewing angle, a uniform luminescence and a low production cost.

NORLED is a Nordic collaboration about the fluorescent silicon carbide material, which is the light emitting material in a new type of white LED for general lighting. The LED has many advantages, mainly that it has a light quality close to the light bulb and can handle the heat which is created in high current LEDs for general lighting purposes.

NORLED project was created in order to understand the science and acceptance of the LED material and its light. The NORLED partners expertise ranges from growth of the material, optical and structural characterization to energy consideration related to houses and buildings, and the acceptance in society and use in new armature and room design.

NORLED collaborates with Prof. Satoshi Kamiyama at Meijo university, Japan (the group that invented the modern nitride growth technology which enabled the use of blue light emitting diodes by the work of Isamu Akasaki group). Satoshi Kamiyama has proposed a new LED design based on fluorescent silicon carbide material and new innovations in light excitation and light extraction, which are crucial for the function of the LED diode.

The LED has the following benefits as it:

- produces light with a color quality very close to that produced by incandescent lamps and sun light on the ground
- produces light with a color quality that is stable over time
- produces light with a color quality that is independent of the ambient temperature
- has a spectrum that does not depend on output power or divergence angle
- has a lifetime of 300'000 hours
- may be produced with tolerances such that no binning is necessary

Responsible for this page: Mikael Syväjärvi
Last updated: 2009-11-26