A red phosphor LaSc3(BO3)4:Eu3+ with zero-thermal-quenching and high quantum efficiency for LEDs

A novel red phosphor LaSc3(BO3)4:Eu3+ with high quantum efficiency and zero-thermal-quenching was reported. The crystal structure and electronic structure were investigated by Rietveld refinement method and density functional theory (DFT) calculations. The FE-SEM and TEM analysis were performed to further understand the phase evolution of LaSc3(BO3)4:Eu3+. The energy migration among Eu3+ ions was strongly suppressed due to the long distance of nearest-neighbor Eu3+ sites. The phosphor exhibited high doping concentration of 80 mol%, high quantum efficiency of 88.3% and zero-thermal-quenching until 275 °C. Further researches show that the zero-thermal-quenching behavior is consistent with the thermal disturbance model. Finally, A warm white light LED device with a low correlated color temperature (CCT) of 3438 K and high color rendering index (CRI) of 92.5 was fabricated based on the as-prepared red phosphor LaSc3(BO3)4:Eu3+, indicating that LaSc3(BO3)4:Eu3+phosphor is promising for high-power LEDs. These findings may open up new ways for the exploration of high-performance Eu3+-activated phosphors.