Plasmonic nanostructures of SnO₂:Sb thin film under gamma radiation response

This paper is a part of a natural dye solar cell project. Conductive transparent oxide (CTO) films have been deposited onto preheated glass substrates using a spray pyrolysis technique. The optical, electrical, structural properties as well as thermal annealing and gamma radiation response were studied. The average optical energy gap of doped films for direct allowed and direct forbidden transitions were found to be 3.92 and 3.68 eV, respectively. The plasmon frequency and plasmon energy after doping were found to be 3.48 × 10¹⁴ s ⁻¹ and 0.23 eV. The negative absorbance of the doped film was observed in UV-Vis range after applying both thermal annealing and γ-dose irradiation with 22 kGy. The negative refractive index of the doped film in UV range (220 – 300 nm) is promising for optical applications. The electron mobility μ_e reached a maximum of 27.4 cm² V⁻¹ s⁻¹ for Sb concentration of 10 %. The corresponding resistivity ρ, and sheet resistance R_s reached their minimum values of 1.1 × 10⁻³ Ω cm and 35 Ω sq⁻¹, respectively. The dopant concentration has been increased from 4.13 × 10¹⁹ to 2.1 × 10²⁰cm⁻³. The doped film was found to exhibit three diffraction peaks associated with (2 2 2), (2 0 0), and (2 1 1) reflection planes, of which the peak of (2 2 2) of Sb₂O₃ and the peak of (2 0 0) were very close.