Synthesis and luminescence properties of Li2SnO3:Mn4+ red-emitting phosphor for solid-state lighting

Novel Li2SnO3:Mn4+ red-emitting phosphor is synthesized by high-temperature solid-state reaction method in air. Emission band of Li2SnO3:Mn4+ phosphor withinthe range 620-760 nm is attributed to the E-2 -> (4)A(2) electron transition of Mn4+ ion. Excitation bands peaking at 330, 395, and 480 nm are attributed to 02"-4 Mn4+ charge transfer and (4)A(2) (T-4(1), T-2(1), and T-4(2)) transitions of Mn4+ ion, respectively. The optimal Mn4+ concentration is similar to 0.4 mol% and the corresponding quantum efficiency and lifetime are similar to 42.3% and 16.3 mu s. The influences of temperature and Mn4+ concentration to emission intensity are discussed and analysized. Lifetime data and time resolved spectra confirm that there is only a single type of Mn4+ ion luminescent center in Li2SnO3:Mn4+ phosphor. The influences of the crystal field and the "Mn4+-ligand" bonding to luminescence properties of Mn4+ ion are summaried and analysized. The luminous mechanism is explained via Tanabe-Sugano energy level diagram and the configuration coordinate diagram of Mn4+ in the octahedron. The results indicate thatLi(2)SnO(3):Mn4+ phosphor has a hope to be used as red phosphor candidate for solid-state lighting. (C) 2017 Elsevier B.V. All rights reserved.