A white light emitting solid-state lamp is disclosed having an output of at least 75 lumens per watt at 20 milliamps drive current. The lamp includes a light emitting diode, an encapsulant, and a header. The diode includes a conductive silicon carbide substrate for electrical contact and a Group III...http://www.google.se/patents/US20060138937?utm_source=gb-gplus-sharePatent US20060138937 - High efficacy white LED
