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

Abstract

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 5D0–7F2 transition. The Judd–Ofelt parameters (Ω2, Ω4), transition ratio, and branching ratios (β) of Eu3+-doped Gd2InSbO7 phosphor were calculated on the basis of the emission spectra and decay lifetimes. The optimal content in Gd2InSbO7:xEu3+ 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 (Ra) (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.