Pyrosol deposition of ZnO and SnO2 based thin films:: the interplay between solution chemistry, growth rate and film morphology

Pyrosol is a chemical vapor deposition (CVD) type process where the precursor of the material to be deposited is dissolved in an appropriate solvent. An aerosol of the solution, produced through a piezoelectric transducer, is transported at atmospheric pressure towards a heated substrate where pyrolysis and film deposition occur. The purpose of the present paper is to discuss using two materials, namely zinc oxide and tin oxide, the interplay between solution chemistry, film growth rate and surface morphology. In order to obtain high growth rates, it is preferable to have small and neutral complex molecules in the solution. With respect to film morphology, depending on the type of precursor, either equilibrium or non-equilibrium faces can develop. Moreover, when a polar surfactant such as HCl is present in the pyrolysis region, polar crystal faces can be stabilized during film growth. (C) 2000 Elsevier Science B.V. All rights reserved.