Effect of TiO2 Concentration on the Non-Volatile Memory Behavior of TiO2-PVA Polymer Nanocomposites

In the current work, we report the fabrication of titanium dioxide polymer nanocomposite (TiO2 PNC) memory devices. TiO2 PNCs were fabricated at three different solution volume ratios with polymer polyvinyl alcohol (PVA), i.e. TiO2-PVA :: 1:100, 1:50 and 1:10. The effect of increased concentration of TiO2 nanoparticles (NPs) was studied. TiO2 NPs were synthesized by the sol-gel method. High-resolution transmission electron microscopy images of the prepared TiO2 NPs were acquired. Fluorine-doped tin oxide (FTO)-coated glass was used as a substrate for device fabrication. PNCs were characterized by x-ray diffraction spectroscopy, and the TiO2-PVA (1:10) device was also morphologically characterized by field emission scanning electron microscopy. The thickness of the PNC film is 14 mu m. These devices exhibit bipolar switching behavior, with the maximum ON/OFF current ratio (I-ON/I-OFF) of similar to 10(3) for the FTO/TiO2-PVA (1:10)/Ag device. Current-voltage (I-V) curves show hysteresis as a result of the formation and rupture of conductive filaments due to the migration of oxygen vacancies. Write-read-erase-read test cycles show good repeatability, stability and retention properties. The results thus prove that the TiO2-PVA devices are strong candidates for next-generation non-volatile memory devices because of their large ON/OFF current ratio, repeatability and stability.