Enhanced luminescence performance in double perovskite CaSrLaSbO6: Mn4+ red emission phosphors for indoor plant growth via cation doping

Novel CaSrLaSbO 6 : Mn 4+ red-emitting phosphors with double perovskite structure were successfully synthesized by the high-temperature solid-phase method. CaSrLaSbO 6 :Mn 4+ phosphor showed a broad excitation band with different excitation peaks from 250 nm to 600 nm owing to the Mn 4+ -O 2- charge transfer and 4 A 2g → ( 4 T 1g , 2 T 2g , and 4 T 2g ) transitions of Mn 4+ ions and exhibited intense deep-red emission at 678 nm attributed to the 2 E g → 4 A 2g transition of Mn 4+ ions. To further enhance the performance of the phosphor, a cation doping method was adopted in this paper to synthesize CaSrLa 1- x Ln x SbO 6 : Mn 4+ (Ln = Gd, Y) phosphors. The luminescence intensity of the samples was enhanced after doping with different cations, and the related mechanism was discussed. In addition, the microstructure and crystal field environment were systematically investigated. The luminescence intensity of the CaSrLa 0.85 Y 0.15 SbO 6 : Mn 4+ phosphor was about 1.82 times higher than that of CaSrLaSbO 6 : Mn 4+ phosphor. The emission spectrum of the sample matched well with the absorption band of plant pigments. Furthermore, the plant growth LEDs and light-conversion film were prepared by using the optimized CaSrLa 0.85 Y 0.15 SbO 6 : Mn 4+ . The results indicate that the designed phosphors have great potential applications in agricultural cultivation.