Yttrium incorporated TiO2/rGO nanocomposites as an efficient charge transfer layer with enhanced mobility and electrical conductivity

•Joint approaches of Y3+ ions integrated with rGO in TiO2 resulted in enhanced optical and electrical properties.•Induced oxygen defects improved the electron concentration in the doped TiO2 lattice.•Improved average carrier lifetime of YTO/rGO leads to efficient charge separation and electrical properties. The efficient tuning of defects in the host lattice to obtain the desired electrical and optical properties is the recent trend in the research arena. Here we aim to tune to oxygen vacancies in TiO2 lattice by dopant incorporation and also investigated the influence of rGO on the electrical properties of doped TiO2 lattice. In this paper, Yttrium incorporated TiO2 (YTO) and YTO/rGO nanocomposites are synthesized. YTO and YTO/rGO nanocomposites are characterized by X-Ray Diffraction (XRD), UV-Differential reflectance spectroscopy (UV-DRS), Raman, X-ray photoelectron spectroscopy (XPS), Hall measurement studies, electrical impedance spectroscopic studies and TRPL measurements. Yttrium (6 mol%) in the TiO2 lattice introduces more oxygen defect sites, modifying the charge carrier dynamics of the lattice (improved electron concentration, enhanced electrical properties, lowered the charge transfer resistance). To improve the average lifetime of the charge carrier, YTO was composited with rGO. YTO/rGO nanocomposite formation was confirmed by XPS and Raman analysis. Nyquist plot of YTO/rGO nanocomposites exhibited reduced charge transfer resistance and lesser relaxation time. TRPL measurements of YTO/rGO nanocomposites showed a significant improvement in the average lifetime of the charge carriers from 19.7 ns for YTO to 30.7 ± 0.5 ns. This improved lifetime of electrons in the nanocomposite system signifies efficient charge separation and reduced charge recombination at the YTO and rGO interface, thus proving YTO/rGO nanocomposite as a better electron extraction layer.