Fabrication, structural properties, and tunable light emission of Sm³⁺, Tb³⁺ co-doped SrSnO₃ perovskite nanoparticles

Sm³⁺, Tb³⁺ co-doped SrSnO₃ perovskites were successfully prepared by the sonochemical method and solid-state reactions. X-ray diffraction showed well-defined peak characteristics of the SrSnO₃ orthorhombic phase, while SEM analysis revealed the formation of rod-like structures composed of particles with a mean size of 100 nm. Under the excitation of 325 nm, the photoluminescence spectra exhibited a broad emission band (380–500 nm) related to intrinsic defects and peaks attributed to characteristic electronic transitions of Tb³⁺ (⁵D₄→⁷F₆, 489 nm, ⁵D₄→⁷F₅, 542 nm) and Sm³⁺ (⁴G_5/2→⁶H_5/2, 570 nm, ⁴G_5/2→⁶H_7/2, 605 nm) ions. Through co-doping with these rare earths, the emission from perovskite can be tuned. The obtained chromaticity coordinates are (0.33, 0.31) and (0.34, 0.32) for 4Sm2Tb and 4Sm4Tb perovskites, respectively. It indicates the promising application potential of Sm³⁺, Tb³⁺ co-doped SrSnO₃ as single-phase perovskite for UV excited white light-diodes.