Estudo das propriedades ópticas de colóides de nanopartículas de prata dispersas em BMI.BF4

Abstract

Hybrid nanostructured organic-metallic colloidal systems are among the most promising systems for the development of optical and photonic devices due to the fact that can present improved physical and chemical characteristics in comparison with the separated organic or metallic constituents. However, the optimal choice of the dispersant, stabilizer and particles is still a matter of research in order to obtain more stable hybrid materials with suitable optical properties. In this work we investigate the optical properties of hybrid organic-metallic colloids consisting of silver nanoparticles dispersed in tetrafluoroborate 1-n-butylmethylimidazolium (BMI.BF4). The morphology of the particles produced and their interaction with light were characterized using transmission electron microscopy and UV-VIS absorption spectroscopy. Using the thermally managed Z-scan technique, the electronic contributions to the nonlinear refractive indexes of the BMI.BF4 and colloids with two different nanoparticles filling factors were measured. Open aperture Z-scan measurements were also performed and revealed a weak saturated absorption for the colloid with the highest silver concentration. The potential of these systems for the development of ultra-fast optical switches was also evaluated. The obtained results indicate that these systems are promising candidates to the development nonlinear optical applications.