An organic–inorganic hybrid K(2)TiF(6) : Mn(4+) red-emitting phosphor with remarkable improvement of emission and luminescent thermal stability

A new type of monoethanolamine (MEA) and Mn(4+) co-doped KTF : MEAH(+), Mn(4+) (K(2)TiF(6) : 0.1MEAH(+), 0.06Mn(4+)) red emitting phosphor was synthesized by an ion exchange method. The prepared Mn(4+) co-doped organic–inorganic hybrid red phosphor exhibits sharp red emission at 632 nm and the emission intensity at room temperature is 1.43 times that of a non-hybrid control sample KTF : Mn(4+) (K(2)TiF(6) : 0.06Mn(4+)). It exhibits good luminescent thermal stability at high temperatures, and the maximum integrated PL intensity at 150 °C is 2.34 times that of the initial value at 30 °C. By coating a mixture of KTF : MEAH(+), Mn(4+), a yellow phosphor (YAG : Ce(3+)) and epoxy resin on a blue InGaN chip, a prototype WLED (white light-emitting diode) with CCT = 3740 K and R(a) = 90.7 is assembled. The good performance of the WLED shows that KTF : MEAH(+), Mn(4+) can provide a new choice for the synthesis of new Mn(4+) doped fluoride phosphors.