Spectral conversion with fluorescent microspheres for light emitting diodes.
An innovative spectral conversion scheme for light emitting diodes using fluorescent microspheres has been demonstrated. An optimally mixed proportion of green and red fluorescent microspheres were coated onto a high-extraction-efficiency GaN micro-LED with emission centred at 470 nm. The microspheres self-assemble into ordered hexagonally arrays, forming regular and uniform coating layers. Devices with cool and warm white emission were achieved. The bluish-white LED has a luminous efficacy of 27.3 lm/W (at 20 mA) with CIE coordinates of (0.26, 0.28) and 8500K CCT, while the yellowish-white LED has a luminous efficacy of 26.67 lm/W (at 20 mA) with CIE coordinates of (0.36, 0.43) and 13000K CCT.
Department of Electrical and Electronic Engineering, University of Hong Kong.
K N
KN
Hui
P T
PT
Lai
H W
HW
Choi
D003116:Color; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008029:Lighting / Q000295:instrumentation* / Q000379:methods; D008863:Microspheres; D012666:Semiconductors; D013050:Spectrometry, Fluorescence / Q000295:instrumentation* / Q000379:methods