Enhanced nonlinear optical properties of pure and rare-earth (Eu, Dy, and Sm) doped ZnSnO ₃ nanomaterials for advanced photonic applications

Zinc stannate (ZnSnO 3 -ZS) is a promising nonlinear optical (NLO) material due to its wide bandgap, high transparency, and structural stability. This study explores the impact of rare-earth doping (Eu[Formula: see text], Dy[Formula: see text], and Sm[Formula: see text]) on the NLO properties of ZS NPs synthesized via a solution combustion method using Aloe vera gel extract as a reducing agent. Structural analysis confirms successful doping, with slight lattice distortions enhancing optical responses. Bragg reflections of all the samples confirm the formation of inverse spinel cubic perovskite structure. UV-Visible absorption studies reveal bandgap modulation. The optical energy band gap was found to be 3.11, 3.1, 3.08 and 3.04 eV for ZS, ZS:Eu (9 mol%), ZS:Dy (9 mol%) and ZS:Sm (9 mol%) NPs, respectively. NLO studies using the Z-scan technique indicate significant enhancement in two-photon absorption and reverse saturable absorption, with Sm[Formula: see text] (9 mol%)-doped ZS exhibiting the highest NLO response. These findings suggest that rare-earth doped ZS is a strong candidate for photonic and optoelectronic applications, particularly in laser protection and optical switching.