High thermal stability phosphor: Red-emitting LiBaPO4:Sm3+

Abstract LiBa 1 − x PO 4 : x Sm 3+ phosphors with various concentrations of Sm 3+ ions ( x = 0.01, 0.03, 0.05, 0.07 and 0.09) were successfully synthesized via microwave-assisted sintering at 900 °C for 3 h under an air atmosphere. The concentration quenching effect occurred when the concentration of Sm 3+ ions is x = 0.05. The thermal quenching temperature T 50 was found to be 500 °C, which is higher than that of the commercial YAG phosphor. The high activation energy Δ E of the LiBa 0.95 PO 4 :0.05Sm 3+ phosphor was calculated to be 0.6 eV. Increasing Sm 3+ ions gradually decreased the lifetime of the Sm 3+ ions from 3.13 to 2.95 ms. All the chromaticity ( x , y ) of the prepared LiBa 1 − x PO 4 : x Sm 3+ phosphors are located in the red region (0.57, 0.41). Moreover, the electroluminescence intensities increase as the current increases from 350 to 600 mA, indicating that LiBa 0.95 PO 4 :0.05Sm 3+ phosphor prepared by microwave-assisted sintering exhibits excellent thermal stability, making it suitable for use as luminescent material for WLEDs.