High quantum efficiency and thermal stability Sr3LiNbO6:Mn4+, Zn2+ phosphors for application in indoor plant growth lighting

Abstract

New double perovskite Sr3LiNbO6:x%Mn4+ and Sr3LiNbO6:x%Mn4+, 1.25x%Zn2+ far-red-emitting phosphors were reported for the first time. The phosphors were characterized by XRD, SEM, PL, PLE, UV–vis spectroscopy, CIE color coordinate and internal quantum efficiency (IQE) measurements. Under the excitation of 365 nm light, Sr3LiNbO6:x%Mn4+ phosphors show a strong far-red emission peak at 695 nm, which is suitable for use in indoor plant application. Furthermore, by co-doping of Zn2+ ions, a more homogeneous particle size distribution was obtained and the emission intensity can raise up to 1.29 times that of Mn4+ single-doped samples. The Sr3LiNbO6:0.6%Mn4+, 0.75%Zn2+ phosphor can obtain an IQE of 78.4% and an emission intensity of 80.6% at 423 K from that at 284 K, showing a high luminous efficiency and thermal stability. Finally, a LED lamp was fabricated with the use of far-red-emitting optimized phosphor, which shows an effective promotion on growth rate and content of photosynthesis pigments of wheat. The results show that Sr3LiNbO6:Mn4+, Zn2+ phosphors may have a promising future in the field of agriculture cultivations.