The effects of the nature of dielectric layers on the electric properties of organic thin-film transistor based on octithiophene (8T)

The organic field-effect transistor was made with vapor deposited polycrystalline octithiophene (8T) on two types of dielectric layers. We investigate the effects of dielectric layers on the electrical proprieties of octithiophene (8T) based FETs fabricated at room temperature. Using two types of dielectric materials such as the Polymethyl Methacrylate PMMA and Silicon dioxide SiO2, the I–V characteristics are measured, and the electrical properties are analyzed. An analytical model that describes the operation of octithiophene field-effect transistors (FETs) is presented. This model is based on the variable range hopping in an exponential DOS for organic transistors. The expression of field-effect mobility is determined, using this model.

► Organic thin-film transistors were fabricated with octithiophene and dielectric. ► The performances of the devices were compared with respect to the dielectric. ► An analytical model that describes the operation of octithiophene thin-film-transistors. ► This model is based on the variable range hopping.