Photoluminescence properties of a novel red fluoride K₂LiGaF₆:Mn⁴⁺nanophosphor

Abstract

Red K 2 LiGaF 6 :Mn 4+ phosphors have been synthesized by the facile cation-exchange method. To optimize the optical properties, the phosphors were synthesized by using different reaction conditions. The highest luminescence intensity was increased 3.6 times for the Mn concentration of 1%, reaction temperature of 20 C, and reaction time of 1 h. Replacement of the trivalent Al by Ga resulted in K 2 LiGaF 6 :Mn 4+ having better photoluminescence properties than K 2 LiAlF 6 :Mn 4+ . Furthermore, the studies of the temperaturedependent emission intensity of the phosphors confirmed their good thermal stability, making them promising red phosphor candidates for white light-emitting diodes.

Mn4+-activated Li3Mg2SbO6 as an ultrabright fluoride-free red-emitting phosphor for warm white light-emitting diodes

“…Normally, the LE decreased when mixing the red components into the LED devices due to the Stokes shiing and the weak sensitivity of human eyes to red light, which can explain that the LE of the cold white LED lamp (LE ¼ 158 lm W À1 ) was much higher than that of the warm WLED lamp (LE ¼ 87 lm W À1 ). 57 Even so, the LE value was higher than that of some warm WLEDs fabricated using the Mn 4+ activated oxides or uorides red phosphors which were reported before such as Sr 61 These results conrmed that the LMS:Mn 4+ red phosphors had a promising application in warm WLEDs.…”

Improvement in luminescent properties and thermo-optical conversion mechanism of Na2SiF6:Mn4+,K+@GQDs

“…3e that the three points of the samples are almost overlapping, indicating that their color difference is very small. Moreover, the color purities of the three samples were calculated using eqn (4): 42,43 Fig. 5 PL performances of the three samples at different temperatures, (i) NSF:0.05Mn 4+ , (ii) NSF:0.05Mn 4+ ,0.04K + , (iii) NSF:0.05Mn 4+ ,0.04K + @GQDs 8 mg mol À1: This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence.…”

A universal HF‐free synthetic method to highly efficient narrow‐band red‐emitting A2XF6:Mn4+ (A = K, Na, Rb, Cs; X = Si, Ge, Ti) phosphors

“…In addition, they also show high QE (~90%) and excellent thermal stability . To date, the fluoride‐based phosphors have been extended from A 2 X F 6 : Mn 4+ ( A = NH 4 , K, Na, Rb, Cs; X = Si, Ge, Sn, Ti, Zr) to A 3 B F 6 : Mn 4+ ( A = K, Na, Rb, Cs; B = Al, Ga), A 2 A ′BF 6 : Mn 4+ ( A = K, Na, Rb, Cs; A ′ = Li, Na, K; B = Al, Ga), A 2 C F 7 : Mn 4+ ( A = K, Na, Rb, Cs; C = Nb, Ta), and Li 3 Na 3 Al 2 F 12 : Mn 4+ …”

“…30,32,33 To date, the fluoride-based phosphors have been extended from A 2 XF 6 : Mn 4+ (A = NH 4 , K, Na, Rb, Cs; X = Si, Ge, Sn, Ti, Zr) to A 3 BF 6 : Mn 4+ (A = K, Na, Rb, Cs; B = Al, Ga), A 2 A′BF 6 : Mn 4+ (A = K, Na, Rb, Cs; A′ = Li, Na, K; B = Al, Ga), A 2 CF 7 : Mn 4+ (A = K, Na, Rb, Cs; C = Nb, Ta), and Li 3 Na 3 Al 2 F 12 : Mn 4+ . [34][35][36][37][38][39][40][41][42] In general, highly concentrated and toxic HF is usually used during the synthesis of Mn 4+ -activated fluoride phosphors. 30,32,[42][43][44] To get rid of damages from HF, HF-free synthetic methods need to be developed.…”