Preparation and Luminescence Properties of KY(CO3)2:Sm3+ Novel Red Phosphor
In order to solve the problem of low color rendering index in white LEDs caused by blue-light chips exciting yellow-light phosphors,a novel red-light phosphor KY(CO3)2:Sm3+ was prepared by hydrother-mal method.The crystal structure and luminescent properties of the sample were characterized by X-ray pow-der diffraction,photoluminescence spectroscopy,color coordinates,and fluorescence lifetime measurements.The results showed that the crystal structure of KY(CO3)2 remained unchanged in the presence of Sm3+ dop-ing.With the increase of Sm3+ doping,the luminescence intensity of phosphors initially increased and then de-creased.The optimal doping amount was found to be 10%.The concentration quenching mechanism was at-tributed to the electric dipole-electric dipole interaction by the analysis of Dexter relationship.The dominant fluorescence excitation peaks at 402 nm(6H5/2→4F7/2)and 474 nm(6H5/2→4I13/2)in the monitoring wavelength of 596 nm indicated that the phosphor could be effectively excited by commercial ultraviolet LED and blue LED.The color coordinates of the doped phosphors showed minimal changes in the red region,indicating that KY(CO3)2:Sm3+ could be utilized as red-light phosphors for white LEDs.