THE ROLE OF ANTIMONY IN TAILORING OPTICAL PROPERTIES OF SPRAY PYROLYSIS SYNTHESIZED PbSe/Sb THIN FILMS FOR SOLAR DEVICE OPTIMIZATION

Abstract

In this study, we employed the Spray Pyrolysis Technique to grow thin solid films of both Antimony-doped and undoped PbSe/Sb on glass substrates. The film growth process relied on the decomposition of lead chloride (PbCl₂) and Antimony chloride in the presence of Sodium selenosulphide (Na₂SeSo₃). Ethylene diamine tetra acetic acid (EDTA) was utilized as a complexing agent and pH stabilizer. The determination of the films' band gaps was conducted through absorbance and transmittance measurements using a Unico-UV-2102 PC spectrophotometer, employing normal incident light in the wavelength range of 200-1500 nm. Upon annealing, thin films of undoped PbSe exhibited a higher initial absorbance of 0.70, which decreased with annealing, along with a reduced extinction coefficient from 70 to 65. Conversely, undoped PbSe displayed the highest optical conductivity, peaking at 80.4 Mmho’s at λ = 340 nm, closely followed by annealed undoped PbSe. Antimony-doped PbSe films exhibited higher reflectance, transmittance, refractive index, and real dielectric constant compared to undoped PbSe. However, they had a narrower optical band gap range of 2.2 eV, which further decreased to 2.0 eV upon annealing. Notably, doping lead selenide with antimony expanded the potential applications of the films.