Are you Chih-Hsuan Liu?

Claim your profile

Publications (2)3.11 Total impact

  • [Show abstract] [Hide abstract]
    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.
    IEEE Photonics Technology Letters 05/2010; · 2.04 Impact Factor
  • [Show abstract] [Hide abstract]
    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 20 mA 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.
    Japanese Journal of Applied Physics 01/2010; 49(7). · 1.07 Impact Factor