Optical designs for high-efficacy white-light emitting diodes

摘要

A method for increasing the luminous efficacy of a white light emitting diode (WLED), comprising introducing optically functional interfaces between an LED die and a phosphor, and between the phosphor and an outer medium, wherein at least one of the interfaces between the phosphor and the LED die provides a reflectance for light emitted by the phosphor away from the outer medium and a transmittance for light emitted by the LED die. Thus, a WLED may comprise a first material which surrounds an LED die, a phosphor layer, and at least one additional layer or material which is transparent for direct LED emission and reflective for the phosphor emission, placed between the phosphor layer and the first material which surrounds the LED die.

主权项

1. A lighting system, comprising:
a stack of semiconductor layers comprising an n-doped layer, an active region, and a p-doped layer, the stack configured to emit a pump light; a converting species configured to absorb at least a fraction of the pump light and to emit a converted light; and a substantially transparent material positioned between the stack and the converting species, and defining at least two optically-functional interfaces between the substantially transparent material and the converting species, including an interface between the stack and the substantially transparent material and an interface between the converting species and the substantially transparent material; wherein the at least two optically-functional interfaces are at least partially reflective for the converted light.