Siberian Federal University

Ni-doped SnO2 thin films with nickel concentrations ranging from 0 to 7 at.% were deposited on glass substrates using the solar spray pneumatic technique at 450 ± 15 °C. X‑ray diffraction confirmed that all samples are polycrystalline with a tetragonal rutile SnO 2 structure and a preferred orientation along the (101) plane. The absence of secondary NiO phases indicates successful substitution of Sn +2 ions by Ni+2 ions, which caused a slight reduction in lattice parameters and crystallite size. Optical measurements revealed high transparency in the near infrared region, reaching 80 % for undoped films. The transmittance decreased with increasing Ni content, while the optical band gap narrowed from 3.10 eV to 2.08 eV at 5 at.% Ni due to defect level formation. Electrical conductivity significantly improved with doping, reaching 2.05 × 10⁻³ (Ω·cm)⁻¹ at 5 at.% Ni, followed by a slight decrease at higher concentration. The optimized films exhibit tunable optoelectronic properties suitable for gas sensing, transparent electrodes, and photovoltaic applications