Spray-Pyrolyzed SnO 2 Thin Films Modified with Cobalt for Enhanced Structural and Optical Performance

Cobalt-doped and undoped tin oxide (SnO 2 ) thin films were fabricated via a mobile-nozzle spray pyrolysis technique and annealed at 550 °C to investigate the effects of doping on their structural and optical properties. X-ray diffraction confirmed a polycrystalline tetragonal rutile structure with crystallite sizes ranging from 4.39 to 11.47 nm, while scanning electron microscopy revealed dense, uniform nanograin morphology. Energy-dispersive X-ray spectroscopy verified cobalt incorporation without the formation of secondary phases. Optical measurements using UV-Vis spectroscopy and Tauc analysis indicated that the direct optical band gap could be tuned from 3.98 eV to 4.88 eV by varying the cobalt content, reflecting changes in the electronic structure. These results demonstrate that controlled cobalt doping is an effective strategy for tailoring the structural and optical characteristics of SnO 2 thin films, making them suitable for diverse optoelectronic, sensing, and transparent conducting applications.

• cobalt-doped tin oxide
• SnO2 thin films
• spray pyrolysis
• optical band gap tuning
• rutile structure
• crystallite size
• transparent conducting oxides
• optoelectronic applications
• sensing applications

• ZnO doping and properties
• Thin-Film Transistor Technologies
• Chemical and Physical Properties of Materials
• cobalt-doped tin oxide
• SnO2 thin films
• spray pyrolysis
• optical band gap tuning
• rutile structure
• crystallite size
• transparent conducting oxides
• optoelectronic applications
• Materials Chemistry
• Electrical and Electronic Engineering
• Materials Science
• Engineering