Conduction in thin polymer films

Thin polymer films have been made from a variety of starting monomers and their electrical conduction has been studied.The films are produced both by ultraviolet surface photolysis and by a cold-cathode glow-discharge technique. The samples are made in the form of a capacitor sandwich on a glass substrate with aluminium electrodes. The whole sample is made in a high-vacuum system, without breaking vacuum, using out-of-contact masking techniques.Generally, depending on the starting monomer, the polymer films are short-free down to a thickness of about 100 Å, and electric fields up to 10⁷ V/cm may be sustained.The current/voltage characteristics of the films have been investigated as a function of temperature and thickness. One theory to account for the conduction in these materials is presented and compared with other approaches to the problem.