Characterization of MoO3 thin films deposited by laser ablation

Molybdenum oxide thin films were deposited using the laser ablation technique, at three values of working pressure and four values of the mean kinetic energy (E _k) of the plasma ions. The structural characterization of the films performed by X-ray diffraction and Raman spectroscopies showed the presence of the α–MoO ₃ phase in all cases. On the other hand, the value of the band-gap varied from 2.8 to 3.3 eV, depending on the experimental conditions. The XPS analysis showed a variation of the stoichiometry from MoO _2.5 to MoO _3.4 which could explain the variation of the band-gap.