Morphology of SnO2 layers prepared by the electrospraying pyrolysis method

Abstract

SnO2 layers were prepared using an electrospraying pyrolysis method from a SnCl2-ethanol solution, where the effect of the preparation condition on the morphology was investigated. A substrate temperature and a precursor concentration were the determining factors in the morphology. Cracked films were obtained below 250°C. A unique network structure appeared at 281°C, which resulted from the melting of the SnCl2 and the gas release with the pyrolysis on the substrate surface. Layers prepared above 281°C were composed of ∼100 nm particles. These particles were formed from the electrosprayed droplets during the flight. The electrostatic force affected the accumulation manner of the particles. The preferential landing of arriving particles on those previously deposited on the substrate resulted in dendrite-type thick layers. When the concentration was 5 × 101 mol m-3 and above, shells were formed during the vaporization of the solvent. It brought about unshaped layers embedded with hollow particles.