Non-concentration quenching, good thermal stability and high quantum efficiency of K₅Y(P₂O₇)₂:Eu³⁺/Tb³⁺ phosphors with a novel two-dimensional layer structure

Abstract

Our work provides a new host lattice K5Y(P2O7)2 for both Eu3+ and Tb3+ luminescence, with non-concentration quenching, a high IQE and good thermal stability.

Tuning Emission from Greenish to Blue via Chemical Composition Modulation in Solid Solutions (Sr1–yCay)2Sb2O7:Bi3+ under near-UV Light Excitation

“…Unlike trivalent Eu 3+ or Tb 3+ ions whose luminescent performances are attributed to symmetry forbidden f → f transitions, the Bi 3+ ion has spin allowed transition from 1 S 0 to 3 P 1 . Thus, the Bi 3+ phosphors usually possess strong absorption in the near UV region and may possess higher application values than trivalent Eu 3+ or Tb 3+ doped phosphors. , The other feature is that the 6s and 6p of Bi 3+ are the outmost orbits, making the emitting peak positions susceptible to the coordination environment around Bi 3+ because of the nephelauxetic effect as well as crystal field splitting. For instance, the emitting bands of solid solution phosphors Sr 2– y Ba y LaGaO 5 :0.02 Bi 3+ goes from 465 to 502 nm when Sr is gradually substituted by Ba .…”

Why Do Relative Intensities of Charge Transfer and Intra-4f Transitions of Eu3+ Ion Invert in Yttrium Germanate Hosts? Unravelling the Underlying Intricacies from Experimental and Theoretical Investigations

“…Additionally, in other kinds of hosts especially phosphates, silicates, etc. for example, K 5 Y­(P 2 O 7 ) 2 :Eu 3+ ,YBa 3 (PO 4 ) 3 :Eu 3+ , Na 3 MgZr­(PO 4 ) 3 :Eu 3+ , RbBaPO 4 :Eu 3+ , KCaR­(PO 4 ) 2 (R = Gd and Y):Eu 3+ , Ca 19 Mg 2 (PO 4 ) 14 :Eu 3+ , YPO 4 :Eu 3+ , Ca 2 Ga 2 SiO 7 :Eu 3+ , MgY 4 Si 3 O 13 :Eu 3+ , α-Y 2 Si 2 O 7 :Eu 3+ , Y 4.67 (SiO 4 ) 3 O: Eu 3+ , Ca 3 Te 2 (ZnO 4 ) 3 :Eu 3+ , europium oxalate [Eu 2 (C 2 O 4 ) 3 (H 2 O) 6 ]·4.34H 2 O} n , Sr 2 MgB 2 O 6 :Eu 3+ , La 2 CaB 8 O 16 :Eu 3+ , LiLa 2 BO 5 :Eu 3+ , LiCaBO 3 :Eu 3+ , and SrAl 2 B 2 O 7 :Eu 3+ , a similar kind of phenomenon has been reported. − In spite of so many reports, there have been only few attempts to rationalize this phenomenon. Xin and co-workers attributed this abnormality to induced effective positive charge on europium in YBa 3 (PO 4 ) 3 lattice.…”

Thermally Stable Phosphor KBa2(PO3)5:Eu2+ with Broad-Band Cyan Emission Caused by Multisite Occupancy of Eu2+

“…Another widespread method is to couple a near-ultraviolet (UV) chip with red/green/blue (RGB) phosphors to obtain white light with excellent performance. In order to meet this demand, more and more researchers are attempting to develop new phosphors with low cost, good absorbance, high fluorescence efficiency, and good thermally stability. − Eu 2+ is a good choice as a doping ion in numerous host materials. It consists an electric-dipole-allowed 4f 6 5d 1 → 4f 7 ( 8 S 7/2 ) transition, which makes it possess a large absorption of near-UV and violet-blue light and generate a broad emission band. , …”

“…10.1021/acs.inorgchem.0c00428. Fabricated LEDs' luminescence parameters under different currents, Rietveld refinements of the XRD files for KBP:xEu 2+ (x = 0.005, 0.01, 0.03, and 0.04), emission (λ ex = 260 nm) and excitation (λ em = 613 nm) spectra at room temperature of KBP:0.02Eu, excitation line of BaSO 4 and emission spectrum of the KBP:xEu phosphor collected using an integrating sphere and magnification of the emission spectrum, and normalized PL (PLE) spectra under different excitation (emission) wavelengths (PDF)…”