Abstract
A phosphor-converted light-emitting diode structure with an increased phosphor extraction efficiency owing to the ring remote phosphor structure achieves a maximum luminous efficacy of 145 lm/W at 20mA and a maximum luminous flux of 132 lm at 400 mA. The ring remote phosphor structure consists of an inverted cone lens encapsulant and a surrounding ring remote phosphor layer. Ray-tracing simulations demonstrate that the phosphor extraction efficiency of the ring remote phosphor structure exceeds 93%. A high phosphor extraction efficiency is achieved by decreasing the re-emitting light from the ring remote phosphor layer to the absorptive light-emitting diode (LED) chip. Our results further demonstrate that the ring remote phosphor structure device has a radiation pattern as a bi-wing, which is more appropriate for solid-state lighting owing to the low glare.
Original language | English |
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Pages (from-to) | 721011-721016 |
Number of pages | 6 |
Journal | Japanese Journal of Applied Physics |
Volume | 49 |
Issue number | 7 PART 1 |
DOIs | |
State | Published - Jul 2010 |