| High brightness, short wavelength, light emitting devices have been desired for decades, but the technology to manufacture such devices has only just become available. The basic degradation mechanisms of light emitting diodes (LEDs) made from gallium nitride (GaN) and its alloys are not known. This work presents a study of the degradation of commercially available, GaN LEDs under continuous, long-term, life testing and under high current pulsed testing. The results demonstrate that GaN LEDs should have a significantly longer lifetime than equivalent SiC or ZnSe LEDs because of the material properties of the GaN system despite a high intrinsic defect density. The results indicate that the packaging material used on commercial LEDs will cause output degradation long before the semiconductor materials will. |
