Ring Remote Phosphor Structure for Phosphor-Converted White LEDs

Abstract

An efficient packaging configuration for high-power white light-emitting diodes (LEDs), consisting of an inverted cone lens encapsulant and a surrounding ring remote phosphor layer, is present. Ray-tracing simulations demonstrate that the package extraction efficiency of the ring remote phosphor structure exceeds 93%. With the implementation of the ring remote phosphor structure, the ring remote phosphor device has a maximum luminous efficacy of 145 lm/W at 20 mA and a maximum luminous flux of 132 lm at 400 mA. The enhancements are attributed to reduced absorption of the re-emitting yellow light by the LED chip, and the reduction of the trapping light inside the flat remote phosphor layer in normal remote phosphor structure.