Morphological and electrical characterizations of dip coated porous TiO₂ thin films with different concentrations of thiourea additives for resistive switching applications

Dip coating process was used as a synthesis technique for the fabrication of porous TiO₂ thin films, where titanium (IV) n-butoxide precursor was used along with Pluronic F-127 and thiourea additives. In this research, thiourea to precursor molar ratio was varied from 0 to 10%, whereas the concentration of the F127 was kept as 3 mM. The post-synthesis structural, morphological, optical and electrical characteristics of the porous TiO₂ thin films were investigated. The FESEM micrographs have shown the surface modulation with the different molar ratio of thiourea, whereas the XRD patterns have depicted the evolution of anatase phase of the TiO₂ films. The capacitance–voltage measurements were carried out to study the charge densities associated with the TiO₂ films. It has been revealed that the films, deposited with 8% molar ratio of thiourea, have possessed higher density of oxide and interface charges. The films, synthesized at 8% thiourea, have also shown better bipolar resistive switching properties as revealed from the current–voltage characteristics of TiO₂ memristors.