Synthesis of SnO2 thin layers by sol-gel programmed dip coating method: Effect of deposition precursor on structural and optical properties

Abstract

Tin dioxide (SnO2) is a material belonging to the family of transparent and conductive oxides (OTC). It has the advantage of
being non-toxic and abundant on Earth, having good optical transmission and high electrical conductivity as a transparent
conductive layer. Important advances have been made in its application in the field of solar cells. This paper presents details
on study of dip coated tin oxide SnO2 thin layers prepared on glass substrates. It has been shown that he heat treatment
effect on opto-electrical structural and morphological. X-rays diffraction analysis revealed that a formation of tetragonal
cassiterite structure with a preferred growth orientation according to (101) plane with significant effect of deposition
precursor concentration on crystallites size. The SEM images showed that the films morphology depends on precursor
concentration and is controlled by annealing at 400°C, where, it becomes smoother for higher concentration starting from
0.2 mol. UV-Visible spectroscopy has shown the high transparency of SnO2 films ranging in the domains (65%–75%). For all
films, the optical band gap energy varies randomly with the precursor concentration and has been estimated; conversely, it
increases from 3.73 eV to 3.77 eV.