Spectroscopic investigation of an electrochemically controlled conducting polymer-solid electrolyte junction

We have recently reported a hybrid conducting polymer-solid electrolyte heterojunction in which electronic channel current is controlled by ionic diffusion and redox reactions involving doped polyethyleneoxide and doped polyaniline (PANI). In this paper we demonstrate on the microscopic level the validity of the model we proposed to interpret the electronic behavior of the device we fabricated. In particular, we used resonance and vicinity (surface-enhanced-Raman-scattering like) enhanced micro-Raman spectroscopy to map out the redox state of PANI along the conducting channel, simultaneously with the determination of the voltamperometric characteristics in a potentiostat configuration. The Raman data were complemented as appropriate by the optical and Fourier transform infrared absorption spectroscopies.