Pyrolytic properties of di-n-butyltin(IV) diacetate as a precursor for sprayed SnO2 thin films

Abstract

The saturated vapor pressure and pyrolytic properties of di-n-butyltin(IV) diacetate have been investigated with and without oxygen in order to understand the orientational growth of SnO₂ thin films by spray pyrolysis. The dependence of the saturated vapor pressure on temperature was determined: log P_(evap.)Torr = −2.827 × 10³/T + 7.687. It has been found that the pyrolysis of this compound consisted of two stages: elimination of the n-butyl groups in a temperature range between about 280°and 310 °C, and of the acetoxy groups above 320 °C. Such decompositions were shifted toward lower temperatures under oxygen. It was also found that oxygen in air in addition to intramolecular oxygen contributed to the formation of SnO₂ crystal phase. Moreover, it was suggested that pyrolized chemical species preserving the Sn-O bond probably related the orientational growth of the (200) plane of sprayed SnO₂ thin films.