Surface conductivity and C1s core level measurements were employed to show that surface transfer doping of hydrogen-terminated diamond C(100) can be achieved with a molecular heterojunction formed with C 60F 48 and an intralayer of zinc-tetraphenylporphyrin. Measurement of the shift in the diamond Fermi energy shows that the zinc-tetraphenylporphyrin (ZnTPP) layer modifies the C 60F 48-diamond interaction, modulating the extent of charge transfer between the diamond and the fluorofullerene. In contrast to the case of C 60F 48 acceptors, the presence of a ZnTPP layer prevents the formation of air-induced surface conductivity, showing that the intralayer acts to selectively separate these two doping channels.
Bibliographical noteFunding Information:
We acknowledge financial support of the Australian Research Council.