Modeling of organic thin film field-effect transistors based on pentacene in saturation regime: Effect of light illumination

Abstract

Thin film transistor based on pentacene was fabricated on a SiO2/Si substrate by thermal evaporation method at room temperature. Electrical characteristics of the pentacene transistor subjected to a UV light excitation at a wavelength of 365nm were analyzed. Using the variable range hopping model transport (VRH) we have reproduced the mobility of charge carriers under dark and under light illumination in saturation regime. We have presented a method (differential method) that we can extract electrical parameters of this transistor based on pentacene under dark and under light illumination from the first and the second numerical derivative of electrical measurement ID(VG). Finally, we have extracted the electrical parameters, conductance gch and the total resistance RT, of organic TFTs from output characteristics ID(VD) using numerical fit under dark.