Nb ₂ O ₅ thin films obtained by chemical spray pyrolysis

Nb 2 O 5 thin films have been prepared by chemical spray pyrolysis on fused silica and glass substrates from a 10 −2 M NbCl 5 precursor solution of 50% bidistilled water, 49% ethanol and 1% acetic acid. The films are of compact material with high surface roughness, that decrease with increasing substrate temperature (350 °C to 500 °C) while the deposition velocity decreases. All as‐deposited films are amorphous. Post‐annealing in air to temperatures higher than 500 °C leads to a distorted hexagonal crystal phase. With XPS and depth profiling, the stoichiometry and residuals from the precursor solution in these films have been investigated. In particular, the decomposition of the alcoholic component by post‐annealing could be followed with XPS.