Influence of PMAA-graft-PEO copolymers on the formation of thin ZnO films from aqueous solutions

The microstructure of ZnO thin films was characterized by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The ZnO films were deposited on bare silicon as well as on Si wafers modified with self-assembled monolayers (SAMs) by the thermohydrolysis of zinc salts from aqueous solution with the addition of water-soluble copolymers. The influence of polymethacrylic acid partially grafted with polyethylenoxide side-chains on the morphology of the thin films was investigated. X-ray photoelectron spectroscopy (XPS) was carried out to determine the composition of the thin films. A comparison of the position of the 0 ls peak in as-deposited and annealed films suggests that the copolymer remains attached to the precipitated ZnO particles. After calcination at 723 K the copolymer is completely removed, yielding ZnO films with a thickness of 70 nm. Copyright (C) 2002 John Wiley Sons, Ltd.