Effect of rotational speed on structural, morphological, and optical properties of solgel spin coated Sb doped SnO$_2$ thin films

Antimony doped SnO$_2$ (ATO) films were prepared on glass substrates by spin coating method at rotational speeds from 2000 to 3500 rpm. The impact of rotational speed on physical properties of Sb-doped SnO$_2$ films were reported. XRD profiles of Sb-doped SnO$_2$ films exhibits tetragonal rutile phase structure. The surface morphology shows homogeneous growth of the films with spherical structure, and an agglomeration of grains was observed at higher rotational speeds. Sb-doped SnO$_2$ films prepared at 3500 rpm show an optimum transmittance of 82% at visible region. The optical bandgap energy of Sb-doped SnO$_2$ films were increased from 3.23 to 3.46 eV due to Burstein–Moss (B–M) effect. The electrical resistivity of Sb-doped SnO$_2$ films were increased from 2.80 $\cdot$ 10$^{-4}$ to 3.86 $\cdot$ 10$^{-4}$ $\Omega$ $\cdot$ cm with an increase of rotational speed from 2000 to 3500 rpm. KEYWORDS Sb-doped SnO$_2$ films, X-ray diffraction, surface morphology, optical properties, electrical properties