Optical and photoelectrical studies of gold nanoparticle-decorated C₆₀ films

Optical and photoelectrical studies were performed on octane-1,8-dithiol cross-linked fullerene films, with supported gold nanoparticles (C₆₀-DT-Au). According to high-resolution transmission electron microscopy observations, the average size of obtained gold nanoparticles was about 5 nm, and the shape was spherical. The comparative investigation of optical properties of pristine and cross-linked with octane-1,8-dithiol C₆₀ films, decorated with gold nanoparticles, found the difference in the extinction coefficient spectra, which was observed also in the photocurrent spectra of barrier heterostructure Au/C₆₀/Si. The analysis of dark current-voltage characteristics for Au/C₆₀/Si heterostructures showed that the model for them includes the barrier at the C₆₀/Si interface and internal barriers in the C₆₀ layer, caused by the trapping centers. The hopping mechanism of the current transport in the C₆₀ layer was supplemented with the Poole-Frenkel emission process on these centers, with the barrier height greater for the fullerene C₆₀ film cross-linked with octane-1,8-dithiol.