Patterning and substrate adhesion efficiencies of solid films photodeposited from the liquid phase

We experimentally and theoretically investigated the patterning and adhesion, always assumed and almost never discussed, of coatings photochemically deposited on substrates from photoactive solutions of different compositions and pHs. Considering the well-known deposition of Cr(III) layers from potassium chromate solutions, we analyzed the morphology and properties of the deposit when induced by two interfering continuous Ar+ laser waves. The solubility, patterning, and adhesion are investigated in both organic (acetic acid) and inorganic (HCl) acidic solutions. The photodeposition process is also compared for several types of substrates usually found in the literature (glass, silanized glass, PMMA, silicon wafer, indium tin oxide (ITO), and stainless steel). We demonstrate the major role played by the interaction between the generated coating and the substrate and propose a strategy to find the best conditions for photochemical deposition from the liquid phase, an approach that is mandatory for any application requiring optical recording developments