Enhanced self-activated far-red photoluminescence from Sr3LiSbO6 phosphors by Gd3+ doping for plant growth

Sr3LiSbO6 phosphors were prepared by high temperature solid state reaction method. The crystal phase, morphology and optical properties were characterized by X-ray powder diffraction spectroscopy, scan-ning electronic microscope, absorption and photoluminescence (PL) spectra. The XRD Rietveld refinement was performed to obtain the detailed crystal structure of Sr3LiSbO6. The electronic structure was analyzed by density functional theory (DFT) calculation. Sr3LiSbO6 possessed indirect band structure and the band-gap were determined to be 3.17 eV. Self-activated far-red emissions at 630-800 nm were detected under the excitation at 340 nm, which was proposed to originate from the transition between interstitial oxygen defective state to six hybrid 4d(105)s(0) states of Sb5+ according to the results of PL spectra of samples annealed at different atmospheres. The PL intensity can be significantly enhanced by 2.9 times after doping 2 mol% Gd3+ ions in Sr3LiSbO6. The internal quantum efficiency of Sr3LiSbO6:2 mol%Gd3+ was determined to be 25.2%. The influence of the Gd3+ doping on the self-activated PL lifetimes of Sr3LiSbO6 and the thermal quenching property of Sr3LiSbO6:2 mol%Gd3+ was studied. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

Sr3LiSbO6 phosphors were prepared using high temperature solid state reaction and characterized for their crystal structure, morphology, and optical properties. Doping with Gd3+ ions was found to significantly enhance the photoluminescence intensity and internal quantum efficiency of Sr3LiSbO6. The study also investigated the effects of Gd3+ doping on the photoluminescence lifetimes and thermal quenching properties of Sr3LiSbO6.