Spectroscopically enhanced far-red phosphor Li2Mg3TiO6:Cr3+ and its application prospects to the cold resistance of rice

Abstract

Chemical unit co-substitution is a very effective strategy to improve the properties of phosphors. Due to the mismatch of the radii between substituted ions, unexpected properties are usually produced. Such properties are of profound significance to expand the research field. In this study, Mg²⁺–Ti⁴⁺ in Li₂Mg₃TiO₆:Cr³⁺ was replaced by Al³⁺–Al³⁺ and Ga³⁺–Ga³⁺, while the charge balance was maintained. Ion substitution changed the crystal field environment of activator ions, which increased the luminescence intensity by 180% and 184% respectively, accompanied by a slight decrease in thermal stability. In addition, the quantum efficiency was increased from 35.1% to 73.1%. The electroluminescence spectrum of the encapsulated pc-LED was examined, and the overlap with the absorption profile of the phytochrome P_fr was 61%. In order to verify the application prospects of far-red phosphor a 15 day rice growth experiment was set up to detect surface traits, soluble sugars, soluble proteins, and the expression of OsphyA and OsCBF3 genes. It was demonstrated that rice had significant resistance enhancement under far-red light irradiation.