Electronic and atomic structure of evaporated carbon films

Abstract Carbon films have been prepared at different substrate temperatures (25–800°C) by evaporating carbon from a graphite source with an electron beam evaporation device. The films have been analyzed by in situ electron spectroscopy (UPS, XPS and EELS), ex situ scanning tunneling microscopy (STM) and Raman spectroscopy. The UPS valence band and EELS spectra reveal a gradual transition from a disordered carbon film at room temperature deposition to a polycrystalline graphite-like film at 800°C substrate temperature deposition, in good agreement with the results obtained from Raman spectroscopy. STM images of films deposited at 25°C also exhibit a rather disordered carbon network, whereas with increasing substrate temperature, graphite nanocrystallites with sizes of about 20 nm are formed. A correlation between these different characterization techniques is performed.