ELECTROSTATIC TRAPPING OF SINGLE CONDUCTING NANOPARTICLES BETWEEN NANOELECTRODES

For molecular electronics, one needs the ability to electrically addre ss a single conducting molecule. We report on the fabrication of stabl e Pt electrodes with a spacing down to 4 nm and demonstrate a new depo sition technique, i.e., electrostatic trapping, which can be used to b ridge the electrodes in a controlled way with a single conducting nano particle such as a conjugated or metal-cluster molecule. In electrosta tic trapping, nanoparticles are polarized by an applied electric field and are attracted to the gap between the electrodes where the field i s maximum. The feasibility of electrostatic trapping is demonstrated f or Pd colloids. Transport measurements on a single Pd nanoparticle sho w single electron tunneling coexisting with tunnel-barrier suppression . (C) 1997 American Institute of Physics.