Novel yellowish-orange Sr8Al12O24S2:Eu2+ phosphor for application in blue light-emitting diode based white LED

Insight into the crystal structure and photoluminescence properties of an extremely broadband yellow-emitting phosphor Sr8MgCe(PO4)7:Eu2+

An extremely broadband yellow-emitting phosphor Sr₈MgCe(PO₄)₇:Eu²⁺ has been realized.

La6Si4S17:Ce3+: luminescence and lighting applications of a novel green-emitting phosphor

An efficient green-emitting La6Si4S17:Ce3+ phosphor was synthesized using a solid-state method. The phosphor exhibits a triclinic structure as the main phase. A broad green emission is observed upon excitation at 420 nm with a quantum efficiency of 83%. A white LED fabricated with the phosphor is promising for use in solid-state lighting applications.

(K0.5Na0.5)NbO3:Eu3+/Bi3+: a novel, highly efficient, red light-emitting material with superior water resistance behavior

Materials emitting red light (∼611 nm) under excitation with blue light (440–470 nm) are highly desired for fabricating high-performance white light-emitting diodes (LEDs).

An intense elastico-mechanoluminescence material CaZnOS:Mn2+ for sensing and imaging multiple mechanical stresses

The elastico-mechanoluminescence (EML) properties of CaZnOS:Mn2+ are investigated. The CaZnOS:Mn2+/epoxy resin composite can simultaneously "feel" (sense) and "see" (image) various types of mechanical stress over a wide energy and frequency range (ultrasonic vibration, impact, friction and compression) as an intense red emission (610 nm) from Mn2+ ions. Further, the accurate linear relation between emission intensity and different stress parameters (intensity, energy and deformation rate) are confirmed. The EML mechanism is explained using a piezoelectrically induced trapped carrier excitation mode. All the results imply that CaZnOS:Mn2+ has potential as a stress probe to sense and image multiple mechanical stresses and decipher the stress intensity distribution.

Eu(2+)-activated Sr8ZnSc(PO4)7: a novel near-ultraviolet converting yellow-emitting phosphor for white light-emitting diodes

The crystal structure of Eu(2+)-activated Sr(8)ZnSc(PO(4))(7):Eu(2+) phosphor was refined and determined from XRD profiles by the Rietveld refinement method using a synchrotron light source. This phosphor crystallizes in the monoclinic structure with the I2/a space group. The SZSP:xEu(2+) phosphors showed a broad yellow emission band centered at 511 and 571 nm depending on the concentration of Eu(2+), and the composition-optimized concentration of Eu(2+) in the Sr(8)ZnSc(PO(4))(7):Eu(2+) phosphor was determined to be 2 mol %. The estimated crystal-field splitting and CIE chromaticity coordinates of Sr(8)ZnSc(PO(4))(7):xEu(2+) (x = 0.001-0.05 mol) were 20181-20983 cm(-1) and (0.3835, 0.5074) to (0.4221, 0.5012), respectively, and the emission band showed a redshift from 547 to 571 nm with increasing Eu(2+) concentration. The nonradiative transitions between the Eu(2+) ions in the Sr(8)ZnSc(PO(4))(7) host were attributable to dipole-dipole interactions, and the critical distance was approximately 19.8 Å. The combination of a 400 nm NUV chip with a blend of Sr(8)ZnSc(PO(4))(7):0.02Eu(2+) and BAM:Eu(2+) phosphors (light converters) gave high color rendering indices between 79.38 and 92.88, correlated color temperatures between 4325 and 7937 K, and tuned CIE chromaticity coordinates in the range (0.381, 0.435) to (0.294, 0.310), respectively, depending on the SZSP:0.02Eu(2+)/BAM:Eu(2+) weight ratio. These results suggest that the Sr(8)ZnSc(PO(4))(7):0.02Eu(2+)/BAM:Eu(2+) phosphor blend has potential applications in white NUV LEDs.

The new red-emitting phosphor of oxyfluoride Ca2RF4PO4:Eu3+ (R=Gd, Y) for solid state lighting applications

The novel red-emitting phosphors of Eu3+-activated Ca2RF4PO4:Eu3+ (R=Gd, Y) prepared by a solid-state reaction have been evaluated as a candidate for white solid state lighting. The detailed luminescence properties, e.g., the excitation spectra, the luminescence spectra and quantum efficiency under the excitation of near-UV, and decay lifetimes were reported. The phosphors can be efficiently excited by near UV light and exhibit a dominant emission peaked at 611 nm (5D0-7F2) with CIE coordinates of (x=0.661, y=0.333). The thermal stabilities were investigated from the luminescence intensities, color purity and the decay curves by increasing temperature. The luminescence parameters related to white LEDs applications were compared to some red phosphors and discussed in details. The red-emitting Ca2RF4PO4:Eu3+ (R=Gd, Y) may be potentially useful in the fabrication of white LEDs.