Bonding character of the boron-doped C 60 films prepared by radio frequency plasma assisted vapor deposition

Boron-doped C 60 thin films were synthesized firstly by a radio frequency plasma assisted vapor deposition technique using C 60 as a precursor. The surface morphology of the samples was observed by atomic force microscopy, and their chemical bonding characters were investigated by x-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopy. The results show that the boron atoms are incorporated into the fullerene molecules in the samples, and the boron heterofullerene C 60− n B n was synthesized. Plasma polymerized C 60 molecules were also found in the samples besides the boron heterofullerene. The effects of radio frequency power and the substrate position on the growth of the B-doped C 60 films were studied. The results indicate that the higher energies and densities of the reactive radicals in the plasma are favorable for the formation of the boron heterofullerene C 60− n B n or polymerized C 60 molecules.