Photoluminescence Analysis and Judd–Ofelt Studies in Sr₂MgSi₂O₇:Sm³⁺ Phosphor

The structural and luminescence properties of akermanite type compound Sr₂MgSi₂O₇:Sm³⁺ have been investigated. The crystal structure of Sr₂MgSi₂O₇ has been obtained from the X-ray diffraction data. Sr₂MgSi₂O₇ possesses tetragonal symmetry with space group P \(\overline{4 }\) $\overline{4}$ 2₁ m (No. 113). Judd Ofelt (J-O) analysis of akermanite structured Sm³⁺-doped Sr₂MgSi₂O₇ phosphor synthesized by combustion synthesis followed by a solid-state reaction process is presented. SEM confirms the morphology. The photoluminescence emission (PL) spectra indicate that the phosphor gives orange red emission at 601 nm attributed to transitions ⁴G_5/2 \(\to\) $\to$ ⁶H_5/2. Optimum concentration is found to be 7.0 mol.%. The CIE chromaticity coordinates are (0.57, 0.43). The branching ratio for the transition, ⁴G_5/2 \(\to\) $\to$ ⁶H_7/2, is found to be around 53%, suggesting it as a potential laser material in addition to its use for fabrication of white LED phosphors.