Facile strategy for the fabrication of efficient nonvolatile bistable memory devices based on polyvinylcarbazole–zinc oxide

Abstract

This paper describes the development of polyvinyl carbazoleZnO hybrid nanocomposites (PVZ) comprising electron donor carbazole moiety (p-type) and electron acceptor zinc oxide (ntype) by a facile strategy and demonstrated its application as an active layer in the nonvolatile memory device. The structure and composition of the nanocomposite were studied by UVVisible absorption, photoluminescence, Raman, FT-IR, XRD, SEM, HR-TEM, and AFM. The results suggested that ZnO retains its hierarchical supramolecular porous morphology and wurtzite crystalline phase with defect states in the PVZ hybrid nanocomposite. PVZ exhibited good solubility in dichlorobenzene and memory devices were fabricated by sandwiching PVZ nanocomposites between indium tin oxide and silver electrode (ITO/PVZ/Ag). The conduction mechanism in the devices was manifested by fitting the double logarithmic I-V plots. Slope value of I-V plots suggested conduction mechanism in the devices was followed Ohmic, Poole-Frenkel emission, and trap filled space charge limited conduction which depends on the applied voltage. Endurance performances of the devices were stable for more than 100 cycles having ON/OFF current ratio of 5.2 Â 10 3 and retention time of 10 5 s.1 Introduction Recently, there is growing interest in the investigation of resistive switching memory for the demand of next-generation information and communication technology with high speed, low operation voltage, and high integration density [1][2][3][4]. Electrical resistive memory devices based on hybrid nanocomposites are gaining much attention since they exhibit significant advantages over inorganic semiconductor (metal oxides) based memory materials [5][6][7]. This includes low fabrication cost, printability, good scalability, mechanical flexibility, simple device structures, and high ON/OFF ratio. The electrical resistive switching device is a simple metal-insulatormetal structure with an active layer sandwiched between two electrodes and the resistance of the active layer is changed by applying a bias, constituting the set and reset

Synthesis of Pyrrole-N-vinylcarbazole Neat Copolymer (Py-NVK) and ZnO Nanocomposite (Py-NVK_ZnO)

“…PPy possesses properties apposite for use in sensors [39], actuators [40] and immunosensor [41] applications. Poly-(Nvinylcarbazole) (PNVK) is important for electronic applications owing to easy processability, environmental steadiness and virtuous electro-optical properties with operational stability [42].…”

“…Similarly, literature also mentioned that ZnO nanocomposite N-vinylcarbazole (NVK_ZnO) micro-structure shows nanotubular formations possessing micrometer length with regular diameter. The shady portions represent ZnO nanoparticles and the lighter portion depicts NVK, inferred so, for the electron movement through the organic and inorganic constituent parts varies markedly [42]. The porous spherical particles of ZnO entrenching the polymer matrix enhance the interface interaction.…”

Study of the capacity of poly(N‐vinylcarbazole) derivatives to form honeycomb‐like patterns

“…Poly(N‐vinylcarbazole) (PVK) is a very interesting conductive polymer based on N‐substitution of carbazole intensively used some decades ago. The interest on this polymer has been renewed due to its use in new applications, such as photonic vapor sensors 1 or different types of OLEDs (e.g., phosphorescent organic light‐emitting diodes or quantum dot light‐emitting diode, among others), 2,3 nonvolatile memory devices 4 or perovskite‐based solar cells 5,6 . In fact, over the years, it has been used in a wide range of applications and it presents excellent thermal stability, doping behavior, and UV durable property 7–9 .…”