Highly efficient all‐nitride phosphor‐converted white light emitting diode

Abstract

Abstract In the Editor's Choice [1] the development and demonstration of a highly efficient warm‐white all‐nitride phosphor‐converted light emitting diode (pc‐LED) is presented utilizing a GaN based quantum well blue LED and two novel nitrogen containing luminescent materials doped with Eu 2+ . These novel LEDs are superior to both incandescent and fluorescent lamps and may therefore become the next generation of general lighting sources. The cover picture is an artist's view of the 2‐pc‐LED: On a copper slug and underneath a plastic lens a ‘flip‐chip’ is soldered to metal contacts; ‘flip‐chip’ meaning the substrate on which the stack of GaN and InGaN layers has been deposited is used as light exit, the (bottom) p‐contacts being highly reflective. The color converting phosphors are placed on top of the chip, embedded in silicone. Primary blue as well as color‐converted red and green photons are emitted. The first author, Regina Mueller‐Mach, manages the Charac‐terization Laboratory at Lumileds which runs R&D work on phosphor converted LEDs in close cooperation with Philips Research Laboratories and the Department of Chemistry and Biochemistry of the University of Munich.