A Highly Efficient White Light (Sr₃,Ca,Ba)(PO₄)₃Cl:Eu²⁺, Tb³⁺, Mn²⁺ Phosphor via Dual Energy Transfers for White Light-Emitting Diodes

Abstract

A series of single-phased (Sr3-x,Ca1-y-z,Ba)(PO4)3Cl (SCBPO_Cl):xEu(2+), yTb(3+), zMn(2+) phosphors were synthesized by high-temperature solid-state reaction, and luminescent properties of these phosphors were investigated by means of photoluminescence and microcathode luminescence (μ-CL). Under UV excitation, white-light emission was obtained from triactivated SCBPO_Cl phosphors via combining three emission bands centered at 450, 543, and 570 nm contributed by Eu(2+), Tb(3+), and Mn(2+), respectively. White-light emission with the three emission bands is further demonstrated in the fluorescence microscope images, CL spectrum, and μ-CL mappings, which strongly confirm that the luminescence distribution of as-prepared SCBPO_Cl:xEu(2+), yTb(3+), zMn(2+) phosphors is very homogeneous. Both spectral overlapping and lifetime decay analyses suggest that dual energy transfers, that is, Eu(2+)→Tb(3+) and Eu(2+)→Mn(2+), play key roles in obtaining the white emission. The International Commission on Illumination value of white emission as well as luminescence quantum yield (51.2-81.4%) can be tuned by precisely controlling the content of Eu(2+), Tb(3+), and Mn(2+). These results suggest that this single-phased SCBPO_Cl:xEu(2+), yTb(3+), zMn(2+) phosphor may have a potential application as a near-UV convertible white-light emission phosphor for phosphor-converted white light-emitting diode.

Li4SrCa(SiO4)2:Ce3+, a highly efficient near-UV and blue emitting orthosilicate phosphor

“…Co-doping of Ce 3+ -Tb 3+ -Mn 2+ or Eu 2+ -Tb 3+ -Mn 2+ are the two common strategies to achieve white light through energy transfer from sensitizers to activators in single-phase phosphors [9][10][11][12][13][14][15][16][17][18][19][20][21]. Wherein, Ce 3+ /Eu 2+ acts as a sensitizer and a emission component on the short wavelength side, whose excitation and emission bands can be tuned depending on the hosts.…”

“…Fortunately, the spectral overlaps between the emission band of Ce 3+ /Eu 2+ and the excitation peaks of Tb 3+ or Mn 2+ allow energy transfer from Ce 3+ /Eu 2+ to Tb 3+ and Mn 2+ under a certain interaction, which results in sufficient green and red emissions and can finally make bright white light produced by well adjusting the relative intensities of three emission components in a single-phase phosphor [15][16][17].…”

Influence of Cu+ cations on photoluminescence properties of Tb3+ in Cu+–Na+ ion-exchanged sodium-borosilicate glasses

“…The prolongation of IET may lead to the rapid increase of Cu + cations in the thin layer. Thus, the PL quenching in GCu20 may be ascribed to the Cu + -Cu + internal concentration quenching effect in the thin surface [2,26].…”

“…Over the past decades, trivalent rare-earth (RE) cations activated luminescent materials have been extensively used in the optoelectronic fields [1][2][3][4][5][6]. However, the narrow line width and the low oscillator strength of the parity-forbidden 4f → 4f absorption transitions of RE cations result in a weak absorptivity in the ultraviolet (UV) range [1,4,7,8].…”

Photoluminescence properties and energy transfer behavior of Eu2+/Tb3+ co-doped Ba3Sc(PO4)3 phosphors

“…7 exhibits the room temperature PL decay curves and lifetime of Eu 2+ in BSP:0.05Eu 2+ ,yTb 3+ (y = 0, 0.15, and 0.25) samples. All the decay curves can be well fitted based on a non-exponential which can be expressed by: (22) …”