Flexible resistive switching bistable memory devices using ZnO nanoparticles embedded in polyvinyl alcohol (PVA) matrix and poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS)

Abstract

The resistive switching memory effects in metal-insulator-metal devices with aluminium (Al) as top electrode (TE) and bottom electrode (BE). A solution processed active layer consisting of zinc oxide (ZnO) nanoparticles embedded in an insulating polyvinyl alcohol (PVA) matrix and polymer poly(3,4ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) has been studied by using flexible polyethylene terephthalate (PET) substrates. The current-voltage (I-V) measurements of hybrid Al/ZnO-PVA/PEDOT:PSS/Al/flexible PET substrate device exhibited a non-volatile bistable resistive switching behaviour, which is attributed to the trapping, storage and transport of charges in the electronic states of the ZnO nanoparticles. The performance of hybrid device is significantly enhanced over control Al/ PEDOT:PSS/Al and Al/ZnO-PVA/Al devices due the presence of PEDOT:PSS polymer. This PEDOT:PSS improves the performance of oxygen ions (holes) migration toward BE and protect back oxygen vacancies (electrons) migrate toward BE from ZnO-PVA composites which may reduces the leakage current, as a result, increased the 'ON state/OFF state' current ratio of 7.9 Â 10 3 times. The fabricatedhybrid device showed high ON/OFF switching current ratio larger than five orders of magnitude with low operating voltages. It is observed that, the existence of two conducting states, namely, low conductivity state (OFF state) and high conductivity state (ON state), exhibiting bistable behaviour. The state of the device was maintained even after removal of the applied bias, indicating the non-volatile memory. The observed current-time response showed good memory retention behaviour of the fabricated devices. The excellent stability and retention performances of hybrid device verify the reliability of this device and demonstrate their potential for application in non-volatile bistable memory device. The carrier transport mechanism of the bistable behaviour for the fabricated non-volatile organic bistable devices structures is described on the basis of the I-V experimental results by analyzing the effect of space charge and electronic structure. Interestingly, the device performance was not degraded and remains identical even after bending the device from 60-120 angles, which indicates high potential for flexible non-volatile bistable memory device applications. This demonstration provides a class of memory devices with the potential for future flexible electronics applications. † Electronic supplementary information (ESI) available: Current-voltage (I-V) resistive switching characteristics of S3 device at different concentration of ZnO in ZnO-PVA nanocomposites. See Fig. 3 (a) Schematic diagram of the S3 memory device and molecular structure of PEDOT:PSS films. Current-voltage (I-V) switching characteristics of the (b) S3 memory device, (c) S1 device and (d) S2 device.This journal is Fig. 4 (a) Retention time measurements of the S3 organic bistable device (OBD) with a read voltage of 1 V. (b) Cumulative probability of S3 memory devices. (c) Linear fitt...

Performance Enhancement of Solution-Processed Organic Memories by Exploiting Synergistic Organic–Inorganic Hybrid Composites

“…15−18 The benefits of using PNCs are manifold such as simple processing, economic fabrication cost, large-scale production, high flexibility, and so forth. Moreover, affordable deposition techniques, such as spin-coating, 12 blade-casting, 19 dip-coating, 20 and ink-jet printing, 21 are being followed extensively for simple device fabrication. As per the literature review, numerous charge-trapping materials including binary transition-metal oxides have been thoroughly employed as nanofillers and dispersed in various charge-blocking materials like PMMA, PVA, PVK, PS, and so forth to fabricate memory devices.…”

Resistive switching effect and magnetic properties of iron oxide nanoparticles embedded-polyvinyl alcohol film

“…9 Hmar reported the devices using hybrid composite of ZnO nanoparticles embedded in PVA and PEDOT:PSS with low operating voltage and switching current ratio larger than ve orders of magnitude. 10 The exible devices remain good performance even aer bending the device from 60-120 . M. Rehman et al fabricated the RRAM conguration of PET/Ag/ MoS 2 -PVA/Ag by printing with mechanical robustness via various bending diameters (50-2 mm) for 1500 cycles.…”

Stable Resistive Switching in ZnO/PVA:MoS2 Bilayer Memristor

“…The switching behavior can also be explained through the energy band diagram of the Ag/ZnO/PVA:MoS 2 /ITO device, as presented in Figure 4b. When the voltage is applied to the Ag electrode, electrons can easily pass through the ZnO due to the work functions of Ag (4.2 eV) and ZnO (5.2 eV) being approximate [39]. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of PVA and MoS 2 are shown in Figure 4b [40][41][42][43].…”