Surface transfer doping of diamond with a molecular heterojunction

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(60)F(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(60)F(48)-diamond interaction, modulating the extent of charge transfer between the diamond and the fluorofullerene. In contrast to the case of C(60)F(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. (C) 2012 American Institute of Physics. [doi:10.1063/1.3676445]