The effect of Li⁺ ions on the luminescent properties of a single-phase white light-emitting phosphor α-Sr₂P₂O₇:Dy³⁺

Abstract

Two series of phosphors, α-Sr2(1-x)Dy2xP2O7 and α-Sr2(1-2x)Dy2xLi2xP2O7, with different x values were synthesized successfully using a conventional solid-state method at high temperature for the first time, and their luminescence properties were investigated comparatively. The effect of Li(+) ions on the luminescence properties of Dy(3+) in α-Sr2P2O7 host, including luminescence intensity, optimal doping concentration, concentration quenching mechanism, and decay behavior, was discussed in detail by considering the defect generation in α-Sr2P2O7:Dy(3+), the charge compensation of Li(+) ions and the role of Li2CO3 as solid flux expected in phosphors. The obtained excitation and emission spectra indicate that these as-prepared phosphors can be excited by ultraviolet light and show white light emission due to the combination of the (4)F9/2→(6)H15/2 and (4)F9/2→(6)H13/2 transitions of Dy(3+) ions. The CIE chromaticity coordinates and color correlated temperature of Dy(3+) emission in the phosphor α-Sr2(1-2x)Dy2xLi2xP2O7 (x = 0.03) with optimal fluorescence intensity was also calculated. The present work could be helpful for understanding the effect of the charge compensator (e.g. Li(+) ion) on the luminescent properties of phosphors with non-equivalent ion-displacement and the design of novel phosphors by efficiently taking advantage of charge compensator (e.g. Li(+) ion).

Synthesis and luminescent properties of ZrO2 and Dy3+-activated ZrO2 powders

“…are located at x = 0.39, y = 0.40 under excitation wavelength 351 nm. These coordinates are very close to the yellowish-white region of the color gamut and are closely in agreement with the reported values [26,27]. Therefore, the results indicate that the undoped ZrO 2 can be used in blue luminescent display devices and the Dy 3?…”

Pyrophosphate Phosphor Solid Solution with High Quantum Efficiency and Thermal Stability for Efficient LED Lighting

“…Pyrophosphate phosphor (a-Sr 2 P 2 O 7 :Eu 2+ ) has been recognized as an excellent blue-emitting phosphor. Previous works mainly focused on investigating the thermoluminescence of Sr 2 P 2 O 7 :Cu 2+ , Ln 3+ (Ln = Pr, Nd, Dy, Ho, Er and Tm); long-lasting luminescence by co-doping M 2 P 2 O 7 :Eu 2+ (M = Ca, Sr) with other rare earth ions; the energy transfer by introducing Eu 2+ -Mn 2+ , Ce 3+ -Mn 2+ , or Tb 3+ -Eu 3+ into the crystal structure of Sr 2 P 2 O 7 ; and the luminescent properties of Sr 2 P 2 O 7 single-doped with rare earth ions (such as Eu 2+ , Bi 2+ , Dy 3+ , Tb 3+ , Sm 3+ ) (Yazici et al, 2010;Pang et al, 2009aPang et al, , 2009bYu et al, 2017;Xu et al, 2013Xu et al, , 2015Li et al, 2015;Han et al, 2015;Cao et al, 2015). Among these researches, it has proved that the traps are easily formed in a-Sr 2 P 2 O 7 host, providing a theoretical possibility to achieve superior thermal stability.…”

Synthesis and luminescence properties of single‐component Ca5(PO4)3F:Dy3+, Eu3+ white‐emitting phosphors

“…The type of energy transfer occurring in Ca 5 (PO 4 ) 3 F:Dy 3+ phosphors can likely explain the concentration quenching mechanism. According to Vanuitert, if energy transfer occurs between the same activators, then the relationship between the emission intensity ( I ) and doping concentration can be described by the following equation: …”