A brief review is provided of the ways electrical properties of semiconducting polymers can be exploited. Emphasis is given to the analysis of electrical conductivity data, in particular to the importance of interchain processes that must be considered along with intrachain processes for bulk conductivity. Among the large variety of possible applications of thin films of semiconducting polymers, the focus is placed on recent breakthroughs in producing diodes, field effect transistors and electroluminescent devices out of these materials. The fabrication of ultrathin films from semiconducting polymers, using the Langmuir-Blodgett and the self-assembly techniques, is discussed to illustrate the importance of processibility issues for any real application including these polymers.

The self-assembly technique is employed for producing alternating ultra-thin films of lysozyme and poly(styrene sulfonate) (PSS). The influence of important parameters in the self-assembly process, namely immersion time, drying method, solution pH and ionic strength, on adsorption kinetics is investigated by ultraviolet (UV) spectroscopy. The absorbance increases rapidly in the initial stages of adsorption for all pHs studied, before reaching a plateau indicative of complete adsorption. Adsorption is considerably more effective when the proton concentration in the solution increases, which is attributed to the increase in the positive charge density within the protein molecules. Furthermore, UV absorbance increases linearly with the number of bilayers (lysozyme/PSS), indicating that a constant amount of material is being adsorbed at each deposition process. These results are highly promising as the self-assembled films are of great interest for biotechnology and molecular electronic applications