The role of Trivalent Samarium on La₂MgTiO₆ perovskite for orange – Red emission with 99.99% colour purity

Trivalent samarium ions are doped in the crystal structure of La₂MgTiO₆ prepared via combustion process. The XRD pattern identify the formation of single-phase orthorhombic structure with space group pbnm. Using UV-Visible info, the optical parameters such as the refractive index, bandgap and Urbach energy are computed to be 2.2705, 3.5745 eV and 484 meV respectively. When excited with 405 nm, the PL spectra show three prominent peaks at 564 nm, 601 nm and 647 nm due to ⁴G_5/2→⁶H_5/2, ⁴G_5/2→⁶H_7/2 and ⁴G_5/2→⁶H_9/2 transitions respectively. The optimized doping concentration is estimated 2% resulting from the nearest dipole-dipole exchange mechanism, above which concentration quenching is observed. The CIE and CIEL*a*b* diagram confirm orange-red emission with coordinates (0.5808, 0.4184) and colour purity 99.99%.