Fabrication and Characterization of TiO₂ Thin Film–Nanorod-Based Hybrid Structures for Memristor Applications

A hydrothermal process was used to grow titanium dioxide (TiO₂) nanorods on p-type silicon substrates, and a dip-coating process was then used to fabricate TiO₂ thin film–nanorod hybrid structures. The nanorod-like structures were obtained for processing temperatures of 160°C and 180°C. The thin films were dip-coated on the nanorods with a withdrawal speed of 1 cm/min. Afterwards, thin film–nanorod hybrid structures were annealed at 500°C for 1 h. Morphological characterization carried out by scanning electron microscopy (SEM) studies confirmed the formation of nanorods. XRD and Raman studies confirmed the presence of anatase and rutile phases of TiO₂-based hybrid structures. The oxide charge density (Q_ox) and the interface charge density (D_it) of the hybrid structures were measured from the capacitance–voltage (C–V) plot. Q_ox and D_it were calculated as 2.29 × 10¹² cm⁻² and 0.89 × 10¹² eV⁻¹ cm⁻², respectively, for a temperature of 180°C and growth time of 60 min. The resistive switching properties of TiO₂-based hybrid structures showed a good on/off ratio, and hence the hybrid structure-based device can be considered a suitable element for memory devices.