Synthesis and Characterization of Nanostructured SnO₂ for Photovoltaic Applications

Abstract

Nanostructured tin dioxide (SnO₂) has attracted considerable attention for photovoltaic applications because of its wide band gap, chemical stability, and favourable electron-transport characteristics. In the present study, nanostructured SnO₂ was synthesized through a controlled precipitation route and systematically investigated to establish the relationship between its structural, morphological, optical, and electrical properties. X-ray diffraction analysis confirmed the formation of the tetragonal rutile SnO₂ phase with an average crystallite size of approximately 23.6 nm. Scanning electron microscopy revealed predominantly quasi-spherical to irregular nanoparticles with an average particle size of approximately 28 ± 6 nm, while energy-dispersive X-ray spectroscopy confirmed Sn and O as the principal constituent elements. UV–visible analysis showed a distinct absorption edge near 343 nm, with an estimated optical band gap of 3.62 eV. Electrical measurements demonstrated semiconducting behaviour with a conductivity of approximately 4.39 × 10⁻⁵ S cm⁻¹. The observed properties indicate that crystallinity, nanoscale morphology, interparticle interactions, and defect-related characteristics collectively influence the electrical response of SnO₂. The combination of nanoscale dimensions, high crystallinity, wide optical band gap, and suitable electrical characteristics highlights the potential of the synthesized SnO₂ for photovoltaic applications, particularly as an electron-transport material. The study establishes a structure–property relationship that can support the further optimization of SnO₂-based functional layers for photovoltaic device architectures.