Electrical transport and electrostatic properties of polyimide Langmuir-Blodgett films

The surface potential of polyimide (PI) Langmuir-Blodgett (LB) films on various metal electrodes was examined, and then the spatial distribution of charges in the films was determined. It was found that excess electrons are displaced from electrodes into the films until thermodynamic equilibrium is established at the film/metal interface. The electron transport mechanism through PI LB films sandwiched between noble metal and superconducting electrodes was also examined by means of I-V and d2V/dI2-V measurements. It was concluded that electrons tunnel through PI LB films without loss of energy and that PI LB films can be used as tunnel barriers in inelastic electron tunneling spectroscopy measurements.