High-temperature solid-phase synthesis of eulyite-type Ba3Yb(PO4)3 as a single host for narrow-band Tb3+ green emission

In this work, a series of iso-structural eulyite-type Ba 3 Yb(PO 4 ) 3 :Tb 3+ solid solution phosphors were synthesized via high-temperature solid-phase method. The corresponding unit cell structure, luminescence properties, thermal stability, and chromaticity coordinates of the as-obtained phosphors were systematically investigated. The crystal structure of Ba 3 Yb(PO 4 ) 3 :Tb 3+ was refined by GSAS program, which indicates the oxygen ions in Ba 3 Yb(PO 4 ) 3 are disordered at one C3 site, and the oxygen atoms are distributed at two sites. Under 378 nm ultraviolet excitation, the emission peak of Ba 3 Yb(PO 4 ) 3 :Tb 3+ appears in the range of 450–650 nm, and a characteristic green emission peak appears at 542 nm. Moreover, the luminous intensity of the Ba 3 Yb(PO 4 ) 3 :14 at.% Tb 3+ sample at 160 °C is 87.7% at room temperature, and the quantum yield is 55.8%, which reveals good thermal stability. Our results suggest that the Ba 3 Yb(PO 4 ) 3 :Tb 3+ phosphors are promising high-efficiency green light conversion materials for UV-LED applications.