A Study on the Luminescence and Energy Transfer of Single-Phase and Color-Tunable KCaY(PO₄)₂:Eu²⁺,Mn²⁺ Phosphor for Application in White-Light LEDs

Abstract

Novel single-phased white light-emitting KCaY(PO(4))(2):Eu(2+),Mn(2+) phosphors for light-emitting diode (LED) applications were synthesized by conventional solid-state reaction. The emission hue could be controlled by tuning the Eu(2+)/Mn(2+) ratio via the energy transfer; the the emission hue of KCaY(PO(4))(2):Eu(2+),Mn(2+) varied from blue (0.1853, 0.2627) to white-light (0.3350, 0.3203) and eventually to purple (0.3919, 0.2867). The mechanism of energy transfer from a sensitizer Eu(2+) to an activator Mn(2+) in KCaY(PO(4))(2):Eu(2+),Mn(2+) phosphors was demonstrated to be an electric dipole-quadrupole interaction. Combining a NUV 405-nm chip and a white-emitting KCaY(PO(4))(2):1%Eu(2+),4%Mn(2+) phosphor produced a white-light NUV LED, demonstrating CIE chromaticity coordinates of (0.314, 0.329) and a color temperature of 6507 K.

Structure and photoluminescence properties of novel Sr6Ca4(PO4)6F2:Re (Re = Eu2+, Mn2+) phosphors with energy transfer for white-emitting LEDs

“…[16][17][18] The Mn 2+ ions doped into a sample show a broad band emission, which was assigned from the 4 were used as the precursor materials and mixed them thoroughly for 3 h using a ball mill to obtain homogeneous samples. Aer-wards, the raw materials were transferred to alumina crucibles, with subsequently sintering at 1250 C for 4 h in reducing atmosphere, and then the as-prepared samples were cooled down to normal room temperature.…”

Single-phase white-emitting phosphors Ba3Ce(1−x−y)(PO4)3:xTb3+,yMn2+ and Ba3Ce(1−x−z)(PO4)3:xTb3+,zSm3+: structure, luminescence, energy transfer and thermal stability

“…[5][6][7] This can not only overcome the shortcomings of high correlated color temperature and low color rendering index, but also avoid reabsorption in the host. [8][9][10][11] Generally, energy transfer plays an important role in the optical properties of co-doped luminescent materials, from which we can obtain a tunable color or white emission.…”

EDTA-mediated morphology and tunable optical properties of Eu3+-doped NaY(MoO4)2 phosphor

“…Generally, W-LEDs can be fabricated by combining GaN-based blue chips with YAG: Ce 3? yellow phosphors, but lacks a red component, resulting in a low color rendering index (R a \ 80) and high color temperature (T c [ 7000 K) [6][7][8]. Therefore, it is of high interest to search for a stable redemitting phosphor with a high absorption in the nearultraviolet or blue spectral region [9,10].…”