Investigation of luminescence properties and energy transfer in Sm3+ and Eu3+ co-doped Sr3Y(BO3)3 red phosphors

Abstract A class of Sm3+ and Eu3+ activated novel and efficient Sr3Y(BO3)3 red phosphors were prepared by conventional high-temperature solid-state reaction. The powder XRD patterns, luminescence properties, diffuse reflectance spectra, fluorescence lifetimes, energy transfer mechanism, and quantum efficiency of the phosphors were researched. Under 404 nm excitation, Sm3+ singly doped Sr3Y(BO3)3 phosphors had the critical quenching concentration of about 0.07 mol and emitted orange-red light. The emission spectra of the phosphors observed a series of characteristic emission of Sm3+ and Eu3+. Two strong emission peaks intensities of Sr3Y(BO3)3:xSm3+, yEu3+ phosphors occur around 602 nm and 613 nm and the corresponding red color emission adjust by the Eu3+ concentration. According to analyze the luminescence spectra and the fluorescence lifetimes curves of the Sr3Y(BO3)3:xSm3+, yEu3+ phosphors, the efficient energy transfer proved to be a dipole–dipole mechanism and the effective energy transfer value was calculated to be 55.69% when y = 0.7. The CIE of the Sr2.93Y1-y(BO3)3:0.07Sm3+, yEu3+ red phosphors can be shifted from (0.595, 0.404) to (0.639, 0.361) through changing the doping concentration of the Eu3+ ions. What’s more, the quantum efficiency could attain a higher value under monitoring at the excited wavelength of the sensitizer Sm3+ more than the activator Eu3+. These researches indicate that our synthesized phosphors might be one of the attractive candidates for white LEDs under n-UV and blue excitation.