Study of photoluminescence and nonlinear optical behaviour of AgCu nanoparticles for nanophotonics

Ag+/Cu+ ions were exchanged in a soda-lime glass matrix (pristine sample) by a simple ion-exchange method. The morphology of the AgCu nanoparticles (NPs) was controlled by the influence of UV irradiation for 1 h and 3 h. Spherical shaped AgCu NPs were diffused on a glass surface, as confirmed by transmission electron microscopy. The diffusion behaviour of the AgCu on the glass surface was studied by secondary ion mass spectroscopy, which showed a higher embedding nature at 3h UV irradiation as compared to the pristine sample. The optical emission properties and nonlinear optical behaviour of the AgCu NPs were investigated with respect to the UV irradiated time used, photoluminescence and the Z-scan technique. The total third order nonlinear optical susceptibility (χ(3)) of the AgCu NPs was investigated by evaluating the nonlinear absorption coefficient (β) and refractive index (n2) values. The imaginary (Imχ(3)) and real (Reχ(3)) parts of the nonlinear susceptibility were calculated using β and n2. The UV induced AgCu NPs demonstrated higher values of χ(3) [4.5 × 10-10 and 5.6 × 10-10 esu] when compared to the pristine NPs [5.8 × 10-11 esu] due to larger NP sizes and tuneable surface plasmon resonance of the AgCu NPs after UV irradiation. Such AgCu embedded glass materials. emerging as strong χ(3) materials, will find applications in nanophotonics.