Study of conductivity switching mechanism of CdSe/PVP nanocomposite for memory device application

Polymer nanocomposites are gaining great attention due to their potential applications in next generation electronic memory devices. In the present work, CdSe/PVP nanocomposite (NC) has been synthesized by using Polyvinyl-pyrrolidone (PVP) as a polymer matrix. The as-prepared CdSe/PVP NC has been characterized by X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), UV-VIS absorption and Photoluminescence (PL) spectroscopy. TEM measurements show spherical nature of CdSe nanoparticles with particle size from 4 to 5 nm. The average crystallite size calculated from XRD pattern is 4.38 nm which is in good agreement with TEM results. The bandgap of the CdSe/PVP NC has been calculated by using Tauc's relation from UV-VIS data. The conductivity switching mechanism of the CdSe/PVP NC devices have been studied by Current-Voltage (I-V) and Capacitance-Voltage (C-V) measurements. I-V and C-V characteristics show hysteresis behaviour due to the charge trapping and detrapping in the CdSe nanoparticles. Good reliability and stability of the devices have been confirmed from the retention characteristics. (C) 2014 Elsevier B.V. All rights reserved.