Desired warm white light emission from a highly photostable and single-component Gd2TiO5:Dy3+/Eu3+ nanophosphors for indoor illuminations

Abstract

At present, phosphor-converted white light-emitting diodes (pc-WLEDs), developed by combining an ultraviolet (UV)/near-UV (NUV) LED and a single-component white emitting phosphor, have attracted significant interest and are emerged as the new-generation green light sources. Herein, we report a highly photostable and novel Gd2TiO5(GT):Dy3+/Eu3+ nanophosphors as single-component white emitting phosphors by sol-gel route. Based on X-ray diffraction pattern, Rietveld refinement is performed to authorize the orthorhombic phase of the GT nanophosphors. The nanosized particles with nearly spherical morphology is perceived after annealing at 1100 degrees C. The Dy3+ and Eu3+ ions individually-doped GT nanophosphors exhibited pleasant white and reddish-orange emissions by monitoring with their respective excitation wavelengths. Tunable white light emission is achieved by co-doping the various concentrations of Eu3+ ions to the optimized GT:1.5Dy(3+) nanophosphors under both UV (270 nm) and NUV (362 nm) excitations. The energy transfer probability is discussed and the energy transfer efficiency from Dy3+ to Eu(3+ )ions is calculated from the luminescence decay profiles. On rising the Eu(3+ )ions content from 0.25 to 6 mol%, the energy transfer efficiency is increased from 14% to 73% for co-doped GT nanophosphors. Besides, the optimized samples of Dy3+ and Eu3+ ions individually-doped and co-doped GT samples exhibited high quantum efficiencies and increased photostability. Thus, the acquired results signifying that these GT:Dy3+/Eu3+ nanophosphors can serve as potential single-component white emitting phosphors for UV and/or NUV-based pc-WLEDs. (C) 2021 Elsevier B.V. All rights reserved.