The effect of citric ion on the spin-sprayed ZnO films: IR and XPS study for the organic impurities

摘要

ZnO films with controlled microstructures and crystal orientations were fabricated on nonseeded substrates by a spin-spray method employing tri-sodium citrate as a structure-directing agent at 90°C. The microstructure of the films changed from a rod array to a dense film by addition of the tri-sodium citrate in the solution. The FT-IR spectra of the films prepared with citrate contained organic molecules including carboxyl groups, being attributed to citric ion. Surface analysis by XPS indicated that the adsorbed citric ions were estimated to form zinc-citrate complex including ammonium ion or ammonium citrate.