Electrical properties of covalently linked silicon polypyrrole junctions

Electrodeposited polypyrrole films were formed on chemically modified hydro gen-terminated silicon surfaces that expose tethered pyrrole units. Semicon ductor/polypyrrole junctions on the native and modified substrates exhibit diode-like characteristics, with those on the latter substrate exhibiting h igher current densities and better ideality factors. Impedance measurements revealed that the improved electrical properties of junctions on the modif ied substrates were not due to a change in barrier height but rather a cons equence of incorporating sites on the silicon surface where the polymer and semiconductor have direct contact. (C) 1999 American Institute of Physics. [S0003-6951(99)02625-X].