Synthesis and structural/microstructural characteristics of antimony doped tin oxide $(Sn_{1-x}Sb_{x}O_{2-\delta})$

TL;DR

This study synthesizes antimony-doped tin oxide samples, analyzing their structural, morphological, and optical properties, revealing that Sb doping increases grain size and bandgap without altering the main phase.

Contribution

It provides detailed microstructural and optical characterization of Sb-doped SnO2, highlighting how doping influences grain morphology and bandgap expansion.

Findings

Grain size increases with Sb doping.

Bandgap widens from 3.367 eV to 3.558 eV with increased Sb.

No change in overall crystal structure up to x=0.30.

Abstract

Bulk samples of $(Sn_{1-x}Sb_{x}O_{2-\delta})$ with x = 0.00, 0.10, 0.20, 0.30 are synthesized by solid-state reaction route. Samples were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV-Vis spectroscopy. The x-ray diffraction patterns indicate that the gross structure/phase of $(Sn_{1-x}$ $Sb_{x}O_{2-\delta})$ do not change with the substitution of antimony (Sb) up to x = 0.30. The surface morphological examination with SEM revealed the fact that the grain size in the antimony doped sample is larger than that of undoped one and hence pores/voids between the grains increase with Sb concentration up to 0.30. TEM image of undoped sample indicates that the $SnO_{2}$ grains have diameters ranging from 25 to 120 nm and most grains are in cubic or spherical shape. As antimony content increases, the nanocubes/spheres are converted into microcubes/spheres. The reflectance of $Sn_{1-x}Sb_{x}O_{2-\delta}$ samples increases whereas absorbance of these samples decreases with the increased concentration of antimony (Sb) for the wavelength range 360 - 800 nm. The energy bandgap of Sb doped - $SnO_{2}$ samples were obtained from optical absorption spectra by UV-Vis absorption spectroscopy. Upon increasing the Sb concentration the bandgap of the samples was found to increase from 3.367 eV to 3.558 eV.