Preparation of far-red emitting Ba2YTaO6:Mn4+ phosphors for plant growth LEDs applications

Abstract A series of far-red emitting Ba2YTaO6:Mn4+ phosphors aiming for plant growth LEDs applications was prepared by using the flux method. LiF was found to be the best flux, and its influence on the crystal structure and photoluminescence properties was investigated. Under 325 nm light excitation, the as-prepared phosphors show far-red emission around 692 nm due to the 2Eg→4A2g transition of Mn4+ ions. The optimal Mn4+ doping concentration was determined to be 0.4 mol%, and the appropriate usage of LiF was found in the range of 7-11 mol%. The as-prepared Ba2YTaO6:0.004Mn4+,0.09LiF phosphor shows outstanding water-resistance property compared with commercially used K2SiF6:Mn4+ phosphor. Finally, a far-red emitting LED was fabricated by using a 375 nm near-UV chip with the as-prepared Ba2YTaO6:0.004Mn4+,0.09LiF phosphor.