Effect of gadolinium on tin oxide thin films prepared by nebulizer spray pyrolysis method

Abstract

Gadolinium-doped tin oxide (SnO2: Gd) thin films were prepared by the nebulizer spray pyrolysis technique on glass substrates using tin (IV) chloride pentahydrate (SnCl2·5H2O) and Gadolinium Sulphate Octahydrate as source materials. Different wt % of doping such as (0%, 1%, 2% and 3%) Gadolinium was used to prepare the spray solution, and their effects on structural, morphological, optical, properties were investigated. X-ray diffraction patterns revealed the polycrystalline tetragonal structure of prepared films. The crystallite size value varies due to Gd doing level. SEM images demonstrated well-aligned tetragonal-shaped nano-grains. Optical band gap values were estimated to be in the range of 3.78–3.82 ​eV by Tauc’s plot. The effects of Gd doping level on the SnO2 thin films obtained using an excitation wavelength of 350 ​nm exhibit emission peaks centered at 361 ​nm, 496 ​nm, 520 ​nm, 540 ​nm and 594 ​nm respectively. It’s indicated that SnO2 thin films exhibited a broad dominant peak near 396 ​nm (about 3.14 ​eV). Raman spectroscopy indicates the spectra for as deposited SnO2 is dominated by presence of strong and sharp peak at 2434 ​cm−1 along with the peak of smaller intensity at 482 ​cm−1.