Northern light-emitting diode initiative (NORLED)

The main objective of the project is to investigate and develop an innovative, industrially feasible white light emitting diode material, and understand the growth, doping and physics of their nucleation and luminescence mechanisms. The objective will be achieved by solving the main fundamental tasks, among other related tasks, in a new growth technology: a) Nitrogen and boron doping in 6H-SiC substrates, and their effective luminescence; b) Nitrogen and aluminium doping in 6H-SiC layers, and their effective luminescence; c) The crystal growth of doped 6H-SiC and its structural quality improvement under doping conditions; d) The surface morphology stability under doping conditions of 6H-SiC epitaxial layers. In a collaboration scheme the properties will be studied and provide necessary feedback to the growth. The project will bring the following improvements of white LED functionalities over conventional technologies: 1) Much better color quality rendering index (CRI >99); 2) Better color stability over time and temperature than LEDs on nitrides; 3) Significantly cooler than incandescent lamps, allowing an increased safety factor; 4) Contains no mercury like fluorescent light tubes; 5) The white light will have a comfortable feeling regarding the human sensation and the light quality is close to that produced by incandescent lamps; 6) Spectrum will not depend on output power or divergence angle as in conventional phosphor coated white LEDs; 7) Increase of lifetime up to 300.000 hours. In comparison, an Edison bulb burns approximately 1.000 hours before the tungsten filament brakes. Compact fluorescent lamps typically last for 10.000 hours. LEDs today last for 50.000 and next generation are projected to last for 100.000 hours