Spectral properties and Judd-Ofelt analysis of novel red phosphors Gd2InSbO7:Eu3+ with high color purity for white LEDs

Gd2InSbO7:Eu3+ red phosphors were successfully synthesized via high-temperature solid-state reaction. The phase purity, particle size, and luminescence properties of obtained phosphors were measured and analyzed in detail. The Gd2InSbO7 lattice possesses cubic structure with Fd-3m (227) space group. The phosphors emit bright red emission at 628 nm under 393 nm excitation, and this phenomenon is attributed to the D-5(0)-F-7(2) transition. The Judd-Ofelt parameters (Omega(2), Omega(4)), transition ratio, and branching ratios (beta) of Eu3+-doped Gd2InSbO7 phosphor were calculated on the basis of the emission spectra and decay lifetimes. The optimal content in Gd2InSbO7:xEu(3+) is identified to be 15 mol%. The thermal quenching of Gd2InSbO7:Eu3+ is found to be over 500 K, and its activation energy is 0.26 eV. The Commission Internationale de l'Eclairage (CIE) chromaticity coordinates of Gd2InSbO7:15%Eu3+ are (0.629, 0.371), which are close to ideal red chromaticity coordinates (0.670, 0.330). The fabricated w-LED exhibits good color rendering index (R-a) (86), correlated color temperature (CCT) (6997 K), and CIE chromaticity coordinates (0.302, 0.330). The obtained results demonstrate that Gd2InSbO7:Eu3+ phosphors have potential applications in white LEDs. (C) 2021 The Authors. Published by Elsevier B.V.