Mn-doped Ho2O3 nanoparticles: Structural, linear and nonlinear optical property enhancements for advanced optoelectronic applications

• The effects of Mn doping on the structural, linear, and nonlinear optical properties of Ho 2-x Mn x O 3 nanoparticles . • Mn 3+ doping leads to a slight reduction in lattice parameter and an increase in crystallite size. • The direct optical band gap, estimated using the Tauc model, decreases with increasing Mn content from 3.2691 eV to 2.7470 eV. • The dispersion energy E d increases from 1.14815 eV to 1.8853 eV, while the single oscillator energy E 0 decreases from 3.10816 eV to 2.9192 eV with increasing Mn content. • Mn doping also leads to an enhancement in the static linear refractive index n 0 and the high-frequency dielectric constant ε ∞ . We report on the structural, linear and nonlinear optical properties of Mn-doped Ho 2-x Mn x O 3 ( x = 0.00, 0.05, and 0.10) powders prepared by sol-gel technique. Investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectra and UV–visible spectroscopy measurements. The Rietveld refinements program showed that all the compounds crystallize in the bixbyite crystal structure. As the Mn content increases, the bandgap energy exhibits a lowering from 3.2691 eV to 2.7470 eV as the size of the nanoparticle increases from 32.10 to 48.89 nm. Additionally, we conducted an analysis relating Urbach energy, refractive index , dielectric coefficient, and optical conductivity to the Mn content within the structure. Furthermore, we explored nonlinear optical parameters, including oscillator energy, dispersion energy, static refractive index , and third-order nonlinear optical susceptibility, all as functions of Mn content. The bandgap energy and the effective oscillator energy decreased while The Urbach energy, the dispersion energy, the refractive index and the dielectric constant increased with increasing Mn %. Based on these linear and nonlinear optical properties , Ho 2-x Mn x O 3 is presented as a good choice and a promising candidate for advanced photonic and optoelectronic applications.