Photoelectrochemical Polymerization of Thiophene on Self-Assembled RuL₂(NCS)₂/Di(3-Aminopropyl)Viologen on Indium Thin Oxide

Polythiophene layers were formed on self-assembled monolayers (SAMs)/indium tin oxide (ITO) using photoelectrochemical polymerization. The SAMs on ITO was prepared using Ru(4,4′-dicarboxylic acid-2,2′-bipyridine)₂ (NCS)₂ and di(3-aminopropyl)viologen. The photoelectrochemically polymerized polythiophene layers on SAMs/ITO were characterized using UV-vis. absorption spectroscopy, atomic force microscopy, scanning electron microscopy, and cyclic voltammetry. The polymer layers have thickness of ∼360 nm, a dense surface morphology, optical gap of 2.38 eV, highest occupied molecular orbital of −5.2 eV and lowest unoccupied molecular orbital of −2.82 eV. In photoelectrochemical cells, the polythiophene on SAMs/ITO electrode showed a photocurrent of 5 μA/cm².