Optical enhancement of highly efficient organic–inorganic oxyfluoride red phosphors via the cation co-doping strategy

Abstract

Herein, a new organic cationic matrix [N(CH₃)₄]₃MoO₃F₃ suitable for Mn⁴⁺ doping was constructed. Due to the large steric hindrance of N[CH₃]₄⁺ (TMA), charge compensation defects can be effectively prevented in the heterovalent Mn⁴⁺-doping process, and a high IQE (91.05%) was obtained. Through the cation co-doping strategy, Mg²⁺/Zn²⁺/Li⁺ cations were introduced into the Mo⁶⁺ cationic site, which improved the crystallinity of the matrix and reduced energy losses, so as to improve luminescence intensity, QE, thermal stability, water stability and other spectral properties. Meanwhile, [N(CH₃)₄]₂TiF₆:Mn⁴⁺ phosphors with the same TMA organic cation and equivalent Mn⁴⁺ doping were synthesized for comparison, and the effects of the Mg²⁺ cation co-doping strategy on the spectral properties of phosphors with different matrix types (fluoride/oxyfluoride) and substitution types (equivalent/non-equivalent) were analyzed. These findings provide the basis for the preparation of new luminescent materials. Furthermore, according to the optical properties exhibited by these phosphors, they are packaged into WLED devices with excellent photoelectric properties, which are suitable for indoor lighting and display fields.