Properties of Regioregular Poly(3-alkylthiophene) Schottky Diodes

Abstract
An investigation into the effect of carrier trapping in polymer Schottky diodes is presented. The diodes have been fabricated using regioregular poly(3-octylthiophene) as the semiconductor and aluminium and indium doped tin-oxide as the rectifying and ohmic contacts respectively. The diodes show rectification ratios up to 3–4 orders of magnitude. Evidence for image-force lowering of the Schottky barrier is observed. The frequency dependence of the capacitance, conductance and dielectric loss is analysed, from which detailed information on the metal/semiconductor interface and the doping level is obtained. An equivalent circuit is proposed.