Abstract
A novel single-phase KCa 2 Nb 3 O 10 :Dy 3+ yellow-emitting phosphor can be efficiently excited under 388 nm irradiation. • KCa 2 Nb 3 O 10 :Dy 3+ phosphors have been firstly synthesized using the molten-salt method. • The KCa 2 Nb 3 O 10 :Dy 3+ product shows excellent thermal stability with high temperature quenching temperature. • The KCa 2 Nb 3 O 10 :Dy 3+ product shows rich UV excitation band and yellow light emission. • The CIE color coordinates of prepared KCa 2 Nb 3 O 10 :Dy 3+ phosphors change slightly. A series of Dy 3+ doped KCa 2 Nb 3 O 10 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 KCa 2 Nb 3 O 10 lattice has a perovskite-like structure, which possesses the Cmcm (No.63) space group. The KCa 2 Nb 3 O 10 :Dy 3+ phosphors can be efficiently excited by n -ultraviolet ( n -UV) excitation of 388 nm. Besides, KCa 2 Nb 3 O 10 :Dy 3+ phosphors can emit three dominant peaks centered at 486, 577, and 662 nm, which are ascribed to the 6 H J /2 ( J = 15/2, 13/2, and 11/2) transitions, respectively. The optimum doping concentrations of Dy 3+ ions in the KCa 2 Nb 3 O 10 host are determined to be 0.02 mol. The thermal-quenching temperature ( T 0.5 ) for the KCa 2 Nb 3 O 10 :0.20Dy 3+ sample is estimated to be above 500 K, and the calculated activation energy ( E a ) is 0.29 eV. Furthermore, the Commission International de I'Eclairage (CIE) color coordinates of prepared KCa 2 Nb 3 O 10 :Dy 3+ phosphors change slightly. KCa 2 Nb 3 O 10 :Dy 3+ phosphors possess good color purity, color stability, and low correlated color temperature (CCT). All results indicate that the KCa 2 Nb 3 O 10 :Dy 3+ phosphors are suitable for white light-emitting diodes (w-LEDs) applications.
Published Version
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