Investigation of structural, morphological and spectral characteristics of double perovskite Sr2GdTaO6 phosphors doped with Eu3+, and co-doped Eu3+, B3+ having improved quantum efficiency

• Published in: Journal of materials science. Materials in electronics 2024-12, Vol.35 (34), p.2163, Article 2163
• Main Authors: İlhan, Mustafa, Güleryüz, Lütfiye Feray
• Format: Article
• Language: English
• Subjects: Asymmetry; Boron; Characterization and Evaluation of Materials; Chemistry and Materials Science; Electric dipoles; Energy gap; Europium; Grain growth; Materials Science; Morphology; Optical and Electronic Materials; Parameters; Perovskites; Phosphors; Photomicrographs; Quantum efficiency
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-024-13832-6

The increasing boron effect significantly enhanced the luminescence and asymmetry of double perovskite phosphor. The structural, morphological and spectral characteristics of Sr 2 Gd 1− x TaO 6 : x Eu 3+ , ( x  = 0.5–20 mol%) and Sr 2 Gd 1− x TaO 6 : x Eu 3+ , y B 3+ ( x  = 10 mol%, y  = 0–100 mol%) phosphor series were examined in terms of Eu 3+ increase and B 3+ increase. In XRD results, Eu 3+ doped Sr 2 GdTaO 6 samples exhibited a single-phase up to 20 mol%, and slight impurity phase was formed at high concentration in Eu 3+ , B 3+ co-doped Sr 2 GdTaO 6 series. In SEM micrographs, there was no significant change in grain morphology of Eu 3+ doped grains, whereas the flux effect of boron led to grain growth in Eu 3+ , B 3+ co-doped samples. The optical band gap energy ( E g ) varied in the range of 4.42–4.27 and 4.27–4.08 eV for Eu 3+ doped and Eu 3+ , B 3+ co-doped series, respectively. The maximum increases in emissions depending on Eu 3+ and B 3+ increase were 10 mol% for Sr 2 GdTaO 6 :Eu 3+ and 50 mol% for Sr 2 GdTaO 6 :Eu 3+ , B 3+ , respectively. The increased B 3+ concentration improved the electric dipole transition ( 5 D 0  →  7 F 2 ), and the asymmetry ratio increased from 0.35 to 2.65. Judd–Ofelt (JO) parameters were calculated from the emission spectrum, in which the Ω 2 and Ω 4 parameters for Sr 2 GdTaO 6 :Eu 3+ phosphors are close values, and both parameters increased in Sr 2 GdTaO 6 :Eu 3+ , B 3+ . The quantum efficiency of Sr 2 GdTaO 6 :Eu 3+ phosphors ranged between 49.82 and 93.08%, and the ɳ QE values for Sr 2 GdTaO 6 :Eu 3+ , B 3+ exceeded 100%.