Synthesis and luminescence properties of novel Y2Si4N6C:Sm3+ carbonitride phosphor

Novel Y2Si4N6C:Sm3+ phosphors for white light-emitting diodes (w-LEDs) were prepared by a carbothermal reduction and nitridation method. X-ray diffraction (XRD) and photoluminescence spectra were utilized to characterize the structure and luminescence properties of the as-synthesized phosphors. The emission spectrum obtained by excitation into 291 nm contains exclusively the characteristic emission of Sm3+ at 568, 607 and 654 nm which correspond to the transitions from 4G5/2 to 6H5/2, 6H7/2, and 6H9/2 of Sm3+, respectively. The strongest one is located at 607 nm due to 4G5/2–6H7/2 transition of Sm3+. It was found that concentration quenching occurred as a result of dipole–dipole interaction according to Dexter's theory. The temperature dependence of photoluminescence properties was investigated from 25 to 300 °C and the prepared Y2Si4N6C:Sm3+ phosphors showed superior thermal quenching properties.