Electrochemical studies on photoactive semiconductor Organic/Inorganic hybrid interface consisting of a poly tris[4-(2-Thienyl)phenyl]amine and CdS nanoparticles

• An occlusion electrodeposition method was used to successfully create a photoactive organic/inorganic interface consisting of an organic polymer and CdS nanoparticles. The assembly exhibited reproducible photoelectrochemical activity. Band alignment of the assembly components are discussed.

An organic/inorganic interface (OII) assembly was created with poly(tris(4-(2-Thienyl)phenyl)amine) (PTTPA) and amorphous CdS nanoparticles by an occlusion-electrodeposition (OE) method. The C3-symmetric monomer, tris(4-(2-Thienyl)phenyl)amine (TTPA), was chosen with the assumption that it would form a branched polymeric network suitable for efficient nanoparticle occlusion The assembly was subjected to photoelectrochemical investigation in aqueous electrolytes containing either acetate, nitrate or phosphate counter-anions. The measured photoactivities of the OII suggest that a p-n junction was formed, in part, because of the narrow band bap of CdS. Results also suggest that a hybrid sub-band formed at the interface as the result of alignment of the energy bands of PTTPA and CdS. Furthermore, O2 played an important role in charge separation and transfer processes. We explain the photoactivity of the OII assembly with reference to measured properties including electron affinity, work function and hole/electron barrier heights. The aqueous nano-system was moderately stable, as indicated by the reproducibility of its photoactivity. Thus, OE was an effective method for creating this photoactive OII assembly.