Existing white LEDs use a blue LED chip to stimulate phosphor powder to form white light. The surface coated with a phosphor layer directly affects the colour rendering index, the luminous efficacy and the colour temperature. We have encapsulated a white LED source with chip-on-board packaging to meet the requirements for a high power, high colour temperature, high colour rendering index LED using stacked phosphor coating. This chip-on-board white LED light source can achieve a colour rendering index over 95 and a luminous efficacy over 100 lm/W while the colour temperature is 5700 K. This technology can be widely used in commercial lighting applications where high quality light sources are needed.
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References
1.
WonYHJangHSChoKW. Effect of phosphor geometry on the luminous efficiency of high-power white light-emitting diodes with excellent color rendering property. Optics Letters2009; 34: 1–3.
2.
HeGZhengL. LED white lights with high CRI and high luminous efficacy. Proceedings of the SPIE2010; 7852: 50–54.
3.
Mueller-MachR. Highly efficient all-nitride phosphor-converted white light emitting diode. Physica Status Solidi A2005; 202: 1727–1732.
4.
KuoTWLiuWRChenTM. High color rendering white light-emitting-diode illuminator using the red-emitting Eu(2+)-activated CaZnOS phosphors excited by blue LED. Optics Express2010; 18: 8187–8192.
5.
OhnoY. Color rendering and luminous efficacy of white LED spectra. Proceedings of the SPIE2004; 5530: 88–98.
6.
MirhosseiniRSchubertMFChhajedS. Color rendering ability and luminous efficacy enhancements in white light-emitting diodes. Proceedings of the SPIE2009; 7422: 742212–742212-7.
7.
MirhosseiniRSchubertMFChhajedS. Improved color rendering and luminous efficacy in phosphor-converted white light-emitting diodes by use of dual-blue emitting active regions. Optics Express2009; 17: 10806–10813.
8.
ZhouZWangHZhangJSuJGeP. LED chip-on-board package with high colour rendering index and high luminous efficacy. Lighting Research and Technology. First published 19 April 2017. DOI: 1477153517701535.
9.
Zhang J, Ge P, Zhou Z, Liu D, Wang H. LED chip-on-board packaging technology for strict colour tolerance. Lighting Research and Technology. First published 3 April 2017. DOI: 1477153517702945.
10.
ZhongPHeGZhangM. Spectral optimization of the color temperature tunable white light-emitting diode (LED) cluster consisting of direct-emission blue and red LEDs and a diphosphor conversion LED. Optics Express2012; 20: A684–A693.
11.
WangM-THuangJ-M. Accurate control of chromaticity and spectra by feedback phosphor-coating. Optics Express2015; 23: 11576–11585.
12.
SunC-CChenC-YChangJ-S. Linear calculation model for prediction of color rendering index performance associated with correlated color temperature of white light-emitting diodes with two phosphors. Optical Engineering2012; 51: 0540031–0540036.
