US Patent No. 10,181,551

LED USING LUMINESCENT SAPPHIRE AS DOWN-CONVERTER


Patent No. 10,181,551
Issue Date January 15, 2019
Title Led Using Luminescent Sapphire As Down-converter
Inventorship Gregoire Francois Florent Denis, San Jose, CA (US)
Assignee Lumileds LLC, San Jose, CA (US)

Claim of US Patent No. 10,181,551

1. A light emitting device comprising:light emitting diode (LED) semiconductor layers comprising an N-type layer, an active layer configured to emit a primary light, and a P-type layer; and
luminescent sapphire distinct from a growth substrate for the semiconductor layers, the luminescent sapphire being affixed over a light emitting surface of the LED semiconductor layers,
the LED semiconductor layers and the luminescent sapphire forming part of an LED die, the luminescent sapphire containing oxygen vacancies resulting in F-like centers having defined optical absorption and luminescence emission bands,
the luminescent sapphire configured to absorb a portion of the primary light and down-converts the primary light to emit secondary light, via the F-like centers, such that an emission from the LED die includes at least a combination of the primary light and the secondary light.