Upconversion luminescence enhancement of the ytterbium oxide with gold nanoparticles on anodized titanium surface

This paper presents a study of the cooperative luminescence (upconversion) process of Yb2O3 with gold nanoparticles on the anodized titanium surface. The luminescence of the samples was registered under two-photon excitation with using infrared laser (λ = 980 nm) and a quasi-continuous femtosecond laser (λ = 1030 nm). It was found that the quantum yield of luminescence in the presence of gold nanoparticles increases in 5.6 times fold as a result of non-radiative plasmon energy transfer. The constant of non-radiative dipole-dipole energy transfer was calculated with using the Förster model under the plasmon energy generation. It is also shown that under photoexcitation with wavelength of 980 nm at low temperatures (80 K), the intensity of upconversion luminescence increases according to the quadratic function of the excitation energy, which confirms the existence of upconversion luminescence generation by the mechanism of simultaneous energy transfer involving two Yb3+ ions in the oxide crystal.