Optimized Mn4+ doped Sr9Y2W4O24 perovskite for enhanced far-red-emitting luminescent material

Abstract

In this study, a new perovskite Sr9Y2W4O24:Mn4+ is presented and its photoluminescence properties are examined in conjunction with electron paramagnetic resonance (EPR) analysis for comparison. Sol-gel synthesis resulted in a series of samples, that were characterized in detail using X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FT-IR), diffuse reflectance spectrum (DRS), photoluminescence spectra (PL) and EPR. XRD patterns are consistent with standard data, affirming the tetragonal crystal arrangement of the synthesized samples. The band gap estimation based on DRS indicated a value of 5 eV. PL emission analysis identified a far-red emission peak (2Eg→4A2) at 677 nm, confirms the presence of Mn in the 4+ ionic state in the inorganic matrix. Crystal field analysis also demonstrated the presence of Mn4+ in a strong crystal field environment. Additionally, EPR analysis revealed distinct features of the observed broad line with a width of approximately 400 G and a six-line spectrum with g ∼1.98 characteristic of the Mn4+ doped Sr9Y2W4O24 perovskite. The prevailing evidence strongly suggests the likelihood of Mn4+ dopant ions occupying W6+ sites within the perovskite lattice. The EPR experimental data also confirmed the simulation data indicating the presence of Mn4+ ions in a given inorganic matrix. This investigation provides a comprehensive insight into the structural and spectroscopic properties of Mn4+ doped Sr9Y2W4O24 perovskites, confirming their potential as advanced lighting technologies to facilitate enhanced agricultural practices and plant cultivation.