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.