Influence of cobalt doping level for distinct numbers of dipping with heat-treatment temperature on dip-coated TiO2 thin films elaborated via sol-gel technique on structural optical and electrical characterizations

Abstract

The influence of cobalt doping level for distinct numbers of dipping with heat-treatment temperature (400, 450, and 500 °C) on the characterization of Ti1-xCOxO2 (x = 0, 0.03, 0.05, and 0.07) thin layers have been focused on this investigation. The specimens were studied using Differential scanning Calorimetry, Spectroscopic ellipsometry (SE), X-ray diffraction (XRD), and atomic force microscopy (AFM). Structural properties revealed that deposited thin films display both tetragonal anatase and orthorhombic brookite crystal structure. The surface morphologies of Ti1-xCOxO2 are smoother relative to undoped TiO2 films. The optical transmittance of Ti1-xCOxO2 thin films is around 60–75% in the visible region with an energy band that reduction of 3.29 to 2.95 eV at 500 °C for 7 % at showing their possible feasibility for optoelectronic and photovoltaic gadgets. The electrical characterization reveals a minimum electrical conductivity of 7.90 10−9 (Ω. cm)-1 picked up for the film doped with 5% at Co at 450 °C.