Charge Transfer, Doping, and Interface Morphologies for Al/C60

D.W. OWENS; C.M. ALDAO; D.M. POIRIER; J.H. WEAVER

PHYSICAL REVIEW B - CONDENSED MATTER AND MATERIALS PHYSICS

APS

Año: 1995 vol. 51 p. 17068 - 17072

0163-1829

The electronic properties and morphologies of aluminum-C« interfaces have been studied with photoelectron spectroscopy. The formation of an interface dipole between the first layer of C«and Al establishes the Fermi level as the common energy-level reference. This dipole layer reAects the transfer of -0.2 electrons per first-layer fullerene. Deposition of Al onto C«at 300 K results in the formation of Al clusters on the surface and also limited Al diffusion into the fullerene lattice. These interstitial Al atoms create a solid solution and form donor levels that are thermally ionized. Aluminum overlayer growth at 60 K results in smaller islands and suppressed doping because both surface and bulk diffusion are thermally activated processes. There is no evidence of bulk Al-C«compound formation.