AN INVESTIGATION OF PHOTOASSISTED DIFFUSION OF OXYGEN IN SOLID C-60 FILMS USING RESONANT ALPHA-SCATTERING

The interaction of molecular oxygen with thin C60 films was investigated using the 3.04 MeV resonance in the O-16(alpha, alpha)O-16 elastic scattering reaction to measure the concentration profile of oxygen in the fullerene films. A thin (d almost-equal-to 20 nm) layer containing oxygen was observed on the surface of C60 films (d almost-equal-to 200 nm) exposed to approximately 1 atm of O2 for 1 h in the absence of light. In contrast, oxygen was uniformly distributed throughout the entire film when samples were irradiated for 1 h with either a 488 nm Ar ion laser or Xe lamp in the presence of approximately 1 atm of O2. This O2 uptake was found to be both power dependent and reversible.