Synthesis and Spectroscopic Properties of Sm3+-Activated Li6Y(BO3)3 Phosphor for Light-Emitting Diode Applications

A series of orange-red emitting Li6Y(BO3)3: Sm3+ (LYBO: Sm3+) phosphors were produced via the high temperature solid-state method. The structure, morphology, element distribution and photoluminescent behavior of these phosphors were thoroughly examined. XRD analysis confirmed that all samples exhibited a pure phase. Under 404 nm excitation, the emission spectra included four distinct transitions of Sm3+, attributed to 4G5/2→6H5/2 (565 nm), 4G5/2→6H7/2 (613 nm), 4G5/2→6H9/2 (647 nm) and 4G5/2→6H11/2 (708 nm). The ideal doping level for LYBO: xSm3+ is x = 0.05, and the concentration quenching primarily stems from electric dipole–dipole interactions among the ions. As the amount of Sm3+ dopant was increased, the fluorescence lifetime decreased. The CIE indicates that LYBO: 0.05Sm3+ is located in the orange-red region, exhibiting a high color purity (99%) and low color temperature (1711 K). The phosphor demonstrated excellent thermal stability and its activation energy was 0.3238 eV. In summary, LYBO: Sm3+ is a potential orange-red phosphor that can be coated onto near-ultraviolet chips suitable for W-LEDs.