Advanced Functional Thin Films via Nebulizer Spray Pyrolysis: Synthesis, Structure, and Applications

Abstract Nebulizer-assisted spray pyrolysis (NSP) is a solution-mediated route for producing functional thin films through controlled aerosol generation, droplet transport, solvent evaporation and thermally activated precursor conversion at a heated substrate. Its appeal lies in the relative simplicity of the apparatus, flexibility in precursor chemistry and potential for coating extended substrate areas. Nevertheless, film formation is governed by coupled phenomena—including droplet-size distribution, solvent volatility, precursor speciation, substrate temperature, aerosol residence time and post-deposition treatment—that determine phase constitution, morphology, defect populations and functional response. This review examines NSP as a materials-engineering platform, with particular attention to oxide semiconductors such as ZnO and Al-doped ZnO (AZO), and to spray-pyrolysed chalcogenide absorbers such as Cu₂ZnSnS₄ (CZTS). Published work on solvent-dependent ZnO deposition and AZO coatings is considered alongside the author’s contributions to ZnO, CZTS, ZnTe and magnesium phthalocyanine (MgPc) thin-film research. A necessary distinction is maintained between materials demonstrated by nebulizer/spray pyrolysis and comparative systems prepared by physical vapour deposition: the cited ZnTe and MgPc studies used vacuum or thermal evaporation and are therefore discussed as complementary examples of structure–property engineering, not as NSP demonstrations. The review develops a unified process–composition–structure–defect–property framework, evaluates characterization strategies and identifies research priorities in precursor design, reproducibility, phase verification, scale-up and application-specific optimization.