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.