Illumination-induced charge transfer in polypyrrole–diamond nanosystem

Charge transfer in polypyrrole–diamond system is studied by conductivity measurements of a channel made of H-terminated diamond in the dark and under illumination. Micrometer-sized channels of conductive hydrogen-terminated diamond are lithographically fabricated on the surface of monocrystalline intrinsic diamond crystal by selective oxygen plasma treatment. The channels are interrupted by electrochemically synthesized micrometer-sized polypyrrole clusters. Similar characterizations are performed on channels interrupted by surface oxidation. Based on the increase and spectral response of the photo-current in the system, doping of diamond by charge carriers from polypyrrole is deduced.