Characteristics of Photoelectrochemical Cells with ITO/p-Si Heterojunction Photoelectrodes Coated with Conducting Polymers

Abstract

The Indium Tin Oxide (ITQ)/p-Si heterojunction electrode was coated with polyaniline and its derivatives in order to improve the durability of photoerectrochemical (PEC) cells composed of ITO/p-Si electrode. ITO (containing 5 wt% SnO₂) was evaporated by an electron beam evaporator, onto Si substrate. Conducting polymers were prepared by galvanostatic electropolymerization on ITO/p-Si at 10 μA.cm_-2. A 500 W Xenon lamp with an infrared filter was used for illumination. Although the quantum yield and the energy conversion efficiency of the PEC cell using the polymer-coated electrode were reduced by its higher resistance and photoabsorption of the polymer itseli. However, the stability of the PEC cell was greatly improved. Particularly, th e photocurrent of the PEC composed of ITO/p-Si coated with polyaniline was found to be less, than 20% degradation of the' initial current value after 100 h photoirradiation.