Femtosecond Laser-Induced Shape Change from Gold Nanoshell to Nanotube

Abstract:

Colloidal gold nanoshells prepared by wet chemical method were irradiated using 800 nm femtosecond laser and their shape change was investigated. Results show that the gold nanoparticles of quasi-sphere-shells with 20~50 nm diameter changed to tube structure of 100~200 nm length and 10 nm diameter after femtosecond laser exposure. In the adsorption spectra, the absorption peak of the gold nanoshell at about 800 nm disappeared and a new absorption peak appeared at about 450 nm. The shape change can be attributed to the electrostatic field from the femtosecond laser exposure. With the force of the electrostatic field, nearby gold nanoshells linked each other, and extended along the electrostatic filed direction to form tube structure.

Key words:Au; nanoshell; nanotube; femtosecond laser exposure