Luminescent properties of Ca₃SiO₄Cl₂ co‐doped with Ce³⁺ and Eu²⁺ for near‐ultraviolet light‐emitting diodes

Abstract

Ca3SiO4Cl2 co-doped with Ce(3+),Eu(2+) was prepared by high temperature reaction. The structure, luminescent properties and the energy transfer process of Ca3SiO4Cl2:Ce(3+),Eu(2+) were investigated. Eu(2+) ions can give enhanced green emission through Ce(3+) → Eu(2+) energy transfer in these phosphors. The green phosphor Ca2.9775SiO4Cl2:0.0045Ce(3+),0.018Eu(2+) showed intense green emission with broader excitation in the near-ultraviolet light range. A green light-emitting diode (LED) based on this phosphor was made, and bright green light from this green LED could be observed by the naked eye under 20 mA current excitation. Hence it is considered to be a good candidate for the green component of a three-band white LED.

Review of Cholorosilicates as Phosphor Hosts

“…Luminescence of Ce 3+ has also been reported for this host. [ 47 ] Li et al. studied energy transfer from to Eu 2+ and Mn 2+ .…”

“…Co-doping with Ce 3+ and eventual energy transfer to Eu 2+ was used by some workers to obtain higher intensities and broader excitation spectra. [46,47] The substitution of Ca by Sr, and Cl by F can also enhance the green emission. [48] Ding et al [49] co-doped Ca 3 SiO 4 Cl 2 :Eu 2+ with Mn 2+ to obtain yellow emission.…”

“…[54] Luminescence of Ce 3+ has also been reported for this host. [47] Li et al studied energy transfer from to Eu 2+ and Mn 2+ . [55] Figure 3 includes PL spectra for Ca 3 SiO 4 Cl 2 :Ce 3+ .…”

Crystal structure and luminescence properties of the blue‐green‐emitting Ba9(Lu, Y)2Si6O24:Ce3+ phosphor

“…These drawbacks meant that YAG:Ce 3 + failed to meet indoor lighting requirements that prefer a warm white light with a low CCT (<4000 K) and a high CRI (>80). As an alternative scheme, the combination of a near‐ultraviolet (NUV) LED chip and three‐primary color (red, green, and blue) phosphors can generate an ideal white light with a high CRI and a tunable CCT . In addition, the color of NUV‐based WLEDs is only decided by phosphors, which circumvent the color drift under a fluctuation of working current.…”

“…As an alternative scheme, the combination of a near-ultraviolet (NUV) LED chip and three-primary color (red, green, and blue) phosphors can generate an ideal white light with a high CRI and a tunable CCT. [11][12][13][14][15][16][17][18] In addition, the color of NUV-based WLEDs is only decided by phosphors, which circumvent the color drift under a fluctuation of working current. Thus, researchers have recently focused on novel NUV excited phosphors with excellent luminescence properties and the solid-state solution is an effective method to achieve novel phosphors.…”