ELECTRICAL PROPERTIES OF SOME NEW ORGANIC SEMICONDUCTORS IN THIN FILMS

Organic semiconductors in thin films have been intensively investigated for the last two decades, owing to their possible applications in the field of semiconductor-device technology (thermistors, organic solar cells, thin film transistors, light-emitting diodes, etc.) [1-4]. For many years a considerable attention has been paid to the experimental studies of electrical conduction mechanisms in a large area of organic semiconducting compounds of quite different classes (monomers, polymers, charge transfer complexes, etc.). In the present work the temperature dependence of the electrical conductivity and Seebeck coefficient for two classes of ylids are investigated. Some correlations between values of semiconducting parameters (electrical conductivity, activation energy of electrical conduction, ratio of carrier mobilities, etc.) and chemical structure of the respective ylids are discussed. The studied compounds correspond to the following general molecular formula: where substituents R1, R2 and R3, as well as corresponding melting points are given in Table 1