Relationships between crystallinity, oxygen diffusion and electrical conductivity of evaporated C 70 thin films
Abstract
The kinetics and reversibility of oxygen diffusion into the polycrystalline thin C 70 films have been studied by time dependent electrical conductivity measurements at different temperatures and at low probing electric fields ( E∼2 V cm -1). It has been shown that only the diffusion among film grains is reversible; the diffusion into voids of fullerene structure is much slower and in practice irreversible. Annealing of films in the air at T>380 K leads to formation of a new semiconducting material ( Ea=1.5 eV) stable at ambient conditions. The oxygen diffusion into fcc C 70 crystal lattice has also been studied by computer calculations. A path of diffusion and diffusion coefficients have been found.
- Publication:
-
Solid State Sciences
- Pub Date:
- August 2002
- DOI:
- 10.1016/S1293-2558(02)01358-4
- Bibcode:
- 2002SSSci...4.1009F