In:
Luminescence, Wiley, Vol. 36, No. 5 ( 2021-08), p. 1159-1171
Abstract:
In present work, KNa(SO 4 ) phosphors doped with different concentrations of rare earth Eu 3+ , Sm 3+ and Dy 3+ ions (0.05, 0.1, 0.3, 0.5, 0.7, 1 mol%) were synthesized using a solid‐state diffusion technique. Photoluminescence (PL) investigations were carried out for the whole range of Eu 3+ , Sm 3+ and Dy 3+ ‐doped phosphors; rare earth ions that retained maximum PL intensity were selected for advanced anionic exchange. In the present investigation, phosphors KNa(SO 4 ):Eu 3+ (1 mol%), KNa(SO 4 ):Dy 3 + (0.5 mol%) and KNa(SO 4 ):Sm 3+ (0.3 mol%) had the highest PL intensity, and were therefore selected for further anionic substitution of sulphate anions with different concentrations of vanadate, phosphate, and tungstate anions, such as KNa(SO 4 ) 1‐x (MO 4 ) x : W (where W = Eu 3+ 1 mol%, Dy 3+ 0.5 mol% and Sm 3+ 0.3 mol%; MO 4 = PO 4 , VO 4 , WO 4 ; and x = 0.1, 0.3, 0.5, 0.7, 1). Structural and molecular environments of the substituted phosphors were characterized individually using X‐ray diffraction and Fourier transform infrared spectroscopy. In‐depth morphological investigations of the prepared phosphors were undertaken using scanning electron microscopy. For the principal investigation on enhancement of white light‐emitting diode (w‐LED) performance, the PL properties of all the synthesized phosphors were studied analytically. Emission intensity ratios for KNa(SO 4 ):Eu 3+ 1 mol%, KNa(SO 4 ) 0 (PO 4 ) 1 :Eu 1 mol%, KNa(SO 4 ) 0.9 (VO 4 ) 1 :Eu 1 mol%, and KNa(SO 4 ) 0.9 (WO 4 ) 0.1 :Eu 1 mol% were 1:1.15:1.23:0.08. PL intensity ratios for the phosphors KNaSO 4 :Dy 0.5 mol% and KNa(SO 4 ) 0.9 (PO 4 )0.1:Dy 0.5 mol% was 1:2. The ratio of PL intensity was 1:3.2:0.8 for KNa(SO 4 ):Sm 1 mol%, KNa(SO 4 ) 0.5 (PO4) 0.5 :Sm 0.3 mol%, and KNa(SO 4 ) 0.7 (VO 4 ) 0.3 :Sm 0.3 mol% phosphors, respectively. Chromaticity investigations were carried out using Commission Internationale de l'Éclairage colour co‐ordinate diagrams, which suggested that the prepared Eu 3+ ‐doped and Sm 3+ ‐doped phosphors would be prospective candidates for red and green LEDs, respectively, whereas Dy 3+ ‐doped phosphors showed emission in the blue and yellow regions. The entire study indicated that amalgamation of anionic exchange at a KNaSO 4 phosphor activated with Eu 3+ , Dy 3+ and Sm 3+ rare earth ions could generate and enhance white light emission.
Type of Medium:
Online Resource
ISSN:
1522-7235
,
1522-7243
Language:
English
Publisher:
Wiley
Publication Date:
2021
detail.hit.zdb_id:
2001819-8
SSG:
12
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