Enhanced green emissions and excellent thermal stability of Ce3+-Tb3+ co-activated Na3.6Y1.8(PO4)3 phosphors via high efficiency energy transfer

Abstract

In this paper, the authors synthesized Na3.6Y1.8(PO4)3: Ce3+, Na3.6Y1.8(PO4)3: Tb3+ and Na3.6Y1.8(PO4)3: Ce3+, Tb3+ phosphors (Na3.6Y1.8(PO4)3 abbreviated as NYPO) via a high-temperature solid-phase method and investigated the luminescent properties. NYPO:Ce3+ phosphor has a broad emission band peaking at 379 nm with an optimal doping concentration of Ce3+ being 6 mol%. It is shown that NYPO:Tb3+ phosphor has green emissions peaking at 540 nm with a quenching concentration of Tb3+ being 27 mol%. It is also found that the emissions of Tb3+ in Ce3+-Tb3+ co-activated NYPO phosphors can be enhanced and tuned effectively through an energy transfer (ET) between Ce3+ and Tb3+ with a transfer efficiency as high as 79 %. In addition, NYPO:Ce3+,Tb3+ phosphor shows excellent thermal stability with nearly 100 % retained luminescence even at 498 K, revealing that NYPO:Ce3+,Tb3+ has potential applications in phosphor-converted LEDs (Pc-LEDs).