Semiconductor body and long-lived light emitting device thereon

Abstract From the Canadian patent

An improved semiconductor body upon which a light emitting device can be fabricated where the improvement is a barrier layer, which has a lattice constant different from that of the substrate and buffer layer, interposed between the substrate and the buffer layer. The strain associated with the lattice constant mismatch is believed to provide a trap for defects which migrate out of the substrate into the active region of the light emitting device. Accelerated life tests at 90°C show a significant reduction in the rate of degradation of the spontaneous light output power of light emitting devices incorporating the invention.