New Dy3+-activated KCa2Nb3O10 yellow-emitting phosphors for w-LEDs application: Preparation and optical properties

A series of Dy3+ doped KCa2Nb3O10 niobate phosphors that generated yellow emission was prepared using the molten-salt method. The crystal structure, X-ray diffraction (XRD), optimal concentration, photoluminescence excitation/emission (PLE/PL), and luminescent stability of the prepared phosphors were exhaustively studied. The KCa2Nb3O10 lattice has a perovskite-like structure, which possesses the Cmcm (No.63) space group. The KCa2Nb3O10:Dy3+ phosphors can be efficiently excited by n-ultraviolet (n-UV) excitation of 388 nm. Besides, KCa2Nb3O10:Dy3+ phosphors can emit three dominant peaks centered at 486, 577, and 662 nm, which are ascribed to the 6HJ/2 (J = 15/2, 13/2, and 11/2) transitions, respectively. The optimum doping concentrations of Dy3+ ions in the KCa2Nb3O10 host are determined to be 0.02 mol. The thermal-quenching temperature (T0.5) for the KCa2Nb3O10:0.20Dy3+ sample is estimated to be above 500 K, and the calculated activation energy (Ea) is 0.29 eV. Furthermore, the Commission International de I'Eclairage (CIE) color coordinates of prepared KCa2Nb3O10:Dy3+ phosphors change slightly. KCa2Nb3O10:Dy3+ phosphors possess good color purity, color stability, and low correlated color temperature (CCT). All results indicate that the KCa2Nb3O10:Dy3+ phosphors are suitable for white light-emitting diodes (w-LEDs) applications.

Automated summary

A series of Dy3+ doped KCa2Nb3O10 phosphors with yellow emission were prepared using the molten-salt method. The crystal structure, optimal concentration, photoluminescence properties, and luminescent stability of the phosphors were studied. The results show that the KCa2Nb3O10:Dy3+ phosphors are suitable for white LED applications.