Spectroscopic characterization of electrodeposited poly(o-toluidine) thin films and electrical properties of ITO/poly(o-toluidine)/aluminum schottky diodes

Abstract

Poly(o-toluidine) (POT) thin films were synthesized by electrochemical polymerization under cyclic voltammetric conditions from o-toluidine monomer in an aqueous solution of HCl as a supporting electrolyte. The electrosynthesized films were characterized by UV-Visible, FT-Raman, and FTIR spectroscopies. The optical transmissions of the as-deposited films were measured in the 400-900 nm wavelength range. These measurements showed that the optical band gap of the polymer films is in the order of 2.52 eV. The FT-Raman and FTIR measurements showed that the POT film is composed of imine and amine units. ITO/POT/Al devices were fabricated by thermal evaporation of aluminum circular contacts on films deposited on ITO-coated glass. The nonlinear current-voltage characteristics of these devices indicate a rectifying behavior. The diode parameters were calculated from I-V characteristics using the modified Shockley equation. The measured C-V and C-F characteristics are presented.