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 ⁴G_5/2 to ⁶H_5/2, ⁶H_7/2, and ⁶H_9/2 of Sm³⁺, respectively. The strongest one is located at 607 nm due to ⁴G_5/2–⁶H_7/2 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.