Sol–gel synthesis, structural, morphological and optical properties of Se-doped SnO₂ nanoparticles

In this paper, the preparation of Se-doped SnO₂ nanoparticles (NPs) and their structural, morphological and optical properties have been reported. Se-doped SnO₂ NPs have been prepared from the precursors containing tin chloride dihydrate and selenium dioxide in the presence of ammonium hydroxide as capping agent via sol–gel method. Three samples of Se-doped SnO₂ NPs with selenium concentration of 0.05, 0.10, and 0.15 wt% have been prepared and calcined at 500 °C for 3 h. The physical and chemical properties have been studied by SEM, EDS, XRD and UV–Vis spectroscopy. The SEM study reveals that the size of the nanoparticles is not uniform and the particles are agglomerated. The EDS study confirms the doping of Se in the SnO₂ NPs. The XRD study reveals the formation of nanoparticles with high crystallinity and broadened width. The minimum size of the nanoparticles obtained is found within the range of 12–17 nm. The optical band gap of Se-doped SnO₂ NPs of 0.05, 0.10, and 0.15 wt% Se have been found 3.21, 2.98 and 2.90 eV respectively. It is found that the band gap of Se-doped SnO₂ NPs is decreased from 3.64 eV of pure SnO₂ NPs.