Thermochemical process in preparation of ZnO film by TFA-MOD method

The excess weight loss due to the evaporation of zinc compound is observed in the growth of ZnO film by trifluoroacetate metalorganic deposition (TFA-MOD) method. Higher temperature (>90 °C) aging and/or addition of monoethanolamine (MEA) are effective to prevent the evaporation of zinc compound and increase the yield of ZnO. The mechanism of preventing evaporation is that zinc trifluoroacetate is hydrolyzed into Zn4O(CF3COO)6. A three-dimensional structure of Zn4O(CF3COO)6 is proposed. It is shown that higher temperature aging does harm to the surface morphology of ZnO films. The addition of MEA reduces the required aging temperature thus improves the surface morphology.