Mechanism behind structural changes accompaning the solid-state polymerization in the molybdenum-vanadium mixed oxide films

Abstract

DOI: 10.26456/pcascnn/2023.15.1029 Abstract: In this paper we investigate the changes in the surface topology of inorganic polymer-derived films resulted from photostimulated polymerization. With the use of the atomic-force microscopy, the surface structure changes of mixed molybdenum-vanadium oxide thin films (V2O5:MoO3 = 3:2) resulted from the UV light-induced polymerization was investigated. The analysis of atomic-force images evidenced that the solid-state polymerization in the mixed oxide films obtained by condensation of corresponding oxoacids occurs through 3D mechanism. As the result of exposure, MoO3/V2O5 films lose the intrinsic anisotropy which is due to the directional agglomeration of belt-like mixed oxide oligomers. The photopolymerization processes in the mixed oxide film yield agglomerates of nuclei built from the faceted nanometer-sized pseudocrystallites. The exposure is also accompanied with solid-state recrystallization of initially amorphous oxide resulting in the rougher relief of the exposed film. The selective acidic etching uncovers the latent structure of the film, this etching being accompanied with pseudocrystallite dispergation that results in the smoothing of the microrelief of the oxide film surface. These structural features of photosensitive mixed oxide MoO3/V2O5 films facilitate their application as the inorganic photoresists.

Keywords

• photopolymerization
• molybdenum-vanadium mixed oxides
• thin films
• nanostructure
• inorganic photoresists
• atomic force microscopy