Effect of Li+ doping on the luminescence performance of a novel KAlSiO4:Tb3+ green-emitting phosphor

Abstract

A new green-emitting phosphor, KAlSiO4:1.5 mol% Tb3+, x mol% Li+, was prepared via a high-temperature solid-phase method, and its crystal structure, diffuse reflectance spectrum, and luminescence were studied. The results show that the Li+ doping shifts the strongest diffraction peak to a high angle direction, reducing grain size by 11.4%. The entry of Li2CO3 improves the luminescence performance of KAlSiO4:1.5 mol% Tb3+. At a Li+ concentration of 1.5 mol%, the sample has strong absorption in the ultraviolet light range from 250 to 400 nm. The luminous intensity of the sample at 550 nm approximately quadruples after Li+ doping. Additionally, the colour purity of the sample and the internal quantum yield increase to 83.3% and 42%, respectively. The sample changes colour with time when exposed to air without an obvious fading phenomenon. The emission intensity at 200 °C is 95.1% of its value at room temperature, indicating that the phosphor has excellent thermal stability when x = 1.5. These results show the feasibility of using the silicate phosphor for generating the green light component of white light-emitting diodes for solid-state lighting.

Tailoring the Luminescent Properties of SrS:Ce3+ by Sr-Deficiency and Na+ Doping

“…To further understand the phase structure and site occupation of Ce 3+ ions, Rietveld refinement was performed for the sample with x = 0.01 Ce 3+ doped (SrS:1.0 mol % Ce 3+ , as shown in Figure c). The unit cell volume varies nonlinearly with the increase in RE element doping concentration (Figure S1), suggesting that the Ce 3+ ion could partially occupy atomic sites of the Sr 2+ ion. − Reliability factors including Bragg R -pattern factor ( R p = 2.488%), weighted-profile R factor ( R wp = 1.362%), and goodness-of-fit parameter (χ 2 = 1.27) evidence the excellent quality and the dependability of the refinement’s data. The refined cell parameters are a = b = c = 6.016(3) Å, α = β = γ = 90°, and V = 217.73(2) Å 3 , confirming a cubic rock-salt structure of the as-prepared particle phosphors.…”

Synthesis and photoluminescence properties of a novel green‐emitting LiYGeO4:Tb3+ long afterglow phosphor

“…[ 38,39 ] When the doping concentration was 30%, CIE coordinates were (0.33411, 0.6509), very close to the edge. Further through the colour purity calculation formula [ 40 ] : We calculated the outstanding purity as: 97.28%.…”

“…[38,39] When the doping concentration was 30%, CIE coordinates were (0.33411, 0.6509), very close to the edge. Further through the colour purity calculation formula [40] : color purity…”

Near ultraviolet light excitable highly efficient blue-green multicolour warwickite phosphor, ScCaO(BO3):Ce3+, Tb3+

“…Tb 3+ is a promising green emission ion due to the 4f -4f electron forbidden transition because Tb 3+ -activated phosphors show narrow band green emission with a FWHM value about 15 nm 18 . However, most Tb 3+ -activated phosphors have a weak absorption band in the range of near UV to blue light [19][20] . An energy transfer phenomenon is one of solution to overcome the weak absorption in near UV light region of Tb 3+ 21-23 .…”

“…18 However, most Tb 3+ -activated phosphors have a weak absorption band in the range of near UV to blue light. 19,20 An energy transfer phenomenon is one of the solutions to overcome the weak absorption in the near UV light region of Tb 3+ . 21–23 The energy transfer occurs from donor ions to acceptor ions.…”