Thin Polymer Films for Chemical Sensors

Abstract

In the study thin films of polyimide, fullerenes, polyanilines and their derivatives are considered to create chemical sensors. Various types of chemical sensors in the form of such thin-film electronic devices as a resistor, a capacitor, and a field-effect transistor are considered. The creation of thin films was carried out by vacuum thermal deposition of aluminum from a tungsten basket and organic material from the Knudsen cell. To obtain polymer films, spin coating from solutions was also used. The dependence of the current through resistive structures on the basis of thin films of fullerenes and polyanilines on the relative humidity of air, the concentration of ammonia vapor in air and reaction time of these structures are investigated. Capacitive air humidity sensors were made with a polyimide film as a dielectric and their main characteristics were measured. The current voltage characteristics of a field-effect transistor with a transport layer of a thin film of polyaniline with different values of air humidity are measured. The results of the studies showed the promise of using thin polymer films to create chemical sensors.