Warm-white light-emitting diode with yellowish orange SiAlON ceramic phosphor

Abstract

A warm-white light-emitting diode (LED) without blending of different kinds of phosphors is demonstrated. An approach that consists of a blue LED chip and a wavelength-conversion phosphor is carried out. The phosphor is a newly developed yellowish orange CaEuSiAlON ceramic phosphor with high efficiency. The CIE1931 chromaticity coordinates (x, y) are (0.458, 0.414), the color temperature is 2750 K, and the luminous efficacy of this LED is 25.9 lm/W at room temperature and with a forward-bias current of 20 mA. The chromaticity of the assembled LED is more thermally stable than that of a LED with a conventional oxide phosphor (YAG:Ce) because of the better thermal stability of the oxynitride phosphor.

Emission color tuning of laminated and mixed SiAlON phosphor films by electrophoretic deposition

“…1)-5) Among the nitride/oxynitride luminescent materials, Eu 2+ doped SiAlON phosphors are promising for applications in light-emitting diodes (LEDs), 6)-10) flat light emitting devices and large liquid crystal displays (LCDs). The SiAlON phosphors are generally synthesized by a solid phase reaction in the form of powders; therefore, it is essential to establish the packaging technology for the diversity of applications.…”

Highly efficient non-rare-earth red emitting phosphor for warm white light-emitting diodes

“…Albeit commercialized in recent years, the CaAlSiN 3 :Eu 2 þ phosphor still has several drawbacks: First, its emission spectrum is very broad (full-width at halfmaximum ¼ B80 nm) and a large part of the spectrum is beyond 650 nm in wavelength and insensitive to human eyes [20][21][22] , thereby decreasing the luminous efficiency of radiation (LER) 23 . Second, the absorption of the phosphor covers the spectral range of B200-650 nm; therefore serious re-absorption will take place when this phosphor is mixed with other green or yellow phosphors, which causes colour change and lower luminous efficacy of LEDs 24,25 . Third, the rigorous synthesis conditions of nitride compounds increase its production cost.…”

Novel Coatings for Enhancement of Light-Emitting Diodes (LEDs)

“…al. [27] indicates a SiA1ON host matrix doped with divalent europium, Eu2+ is a promising candidate for this purpose. Figure 2 shows the absorption and emission spectra of Eu2+ doped SiAMON.…”

“…Excitation and emission spectra of the yellowish orange Ca:Eu:SiAlON phosphor [27]. The excitation wavelength is 450 nm for the emission spectrum, and the emission monitoring wavelength is 585 nm for the excitation spectrum.…”