Defect modulation and luminescence improvement of Mn4+-activated La(Mg, Nb)O3 phosphor with improved stability for plant cultivation

Abstract

The use of Mn⁴⁺-activated deep-red phosphors has continued to increase in plant growth lighting. Of all phosphors, the complex perovskite LaMg_0.66Nb_0.34O₃ (LMN) exhibiting high structural tunability is considered one of the most suitable structures. In this study, the representative LMN:Mn⁴⁺ was synthesized and a defect was introduced into the matrix to improve its thermal stability. Moreover, a computation method with density functional theory (DFT) was adopted to acquire the local crystal structure and the results showed that both the emission intensity and the thermal stability of the phosphors clearly improved. Importantly, we found that the emission intensity at 423 K still reached 82.4% of that at 298 K, which is crucial in plant cultivation applications.