Hydrothermal growth of well-aligned TiO2 nanorods on fluorine-doped tin oxide glass

One-dimensional titanium dioxide nanostructures have been studied intensively and extensively due to their outstanding properties and their diverse technological applications in photovoltaic cells. Interestingly, single crystalline TiO2 nanorods (TiO2 NRs) offer more advantageous compared with TiO2 particles and polycrystalline. TiO2 NRs produce direct electrical pathways of photogenerated carriers as well as large surface areas between NRs. This work presents a synthesis of vertically-aligned and uniform TiO2 NRs that were hydrothermally grown on a transparent conductive fluorine-doped tin oxide (FTO) glass substrate. The substrates were seeded with TiO2 compact layer (CL) using titanium (IV) butoxide as a precursor in HCl solution. Various techniques, including field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) were employed to investigate the morphology and crystalline structure of the prepared TiO2 NRs. FE-SEM results revealed that the TiO2 NRs showed a rod-like nanostructure which could increase the accessible surface area. In addition, the effect on Ti initial reactant concentration was optimized to have desirable properties on the TiO2 NRs' density, diameter and length. As a result, the as-prepared TiO2 NRs could have very good prospects in high-performance perovskite solar cell as electron transporting layers. (C) 2019 Elsevier Ltd. All rights reserved.