Advances in flexible non-volatile resistive switching memory based on organic poly (3, 4-ethylenedioxythio phene): Poly (styrenesulfonate) film

Abstract

In this work, the resistive switching memory has been investigated in conducting polymer poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT: PSS) with aluminium (Al) and indium tin oxide (ITO) acting as electrodes. Current-voltage (I-V) characteristics of the fabricated Al/PEDOT:PSS/ITO flexible Polyethylene terephthalate substrate device reveal a non-volatile resistive switching behaviour. The memory device demonstrates resistive switching non-volatile memory with ION/IOFF current ratio between the high resistance state (HRS) and low resistance state (LRS) up to 104. Both the HRS and LRS of the memory devices are stable, showing no significant change in value of ION/IOFF current ratio, which is maintained at 104 in magnitude under continuous read-out testing for 100 cycles at 90º bending angle, and also retention time of 33 min that confirms the device durability and non-volatility. The charge transport mechanism of the fabricated non-volatile organic devices is governed by space-charge limited conduction. It is proposed that the reduction and oxidation of PEDOT:PSS film might be the switching mechanism. Interestingly, the performance of the memory device revealed no detectable degradation and remained identical even after bending the device from 70 to 160° angles, representing excellent flexibility. Besides, the lowest power and the critical compliant current for resistive switching are determined. The power density for 180° (without bending), 160°, 90° and 70° bending angles is ∼ 30 Wm−2. It demonstrates that for a small range of compliance current, our device showed more power capacity with lower voltage consumption, which makes it a potential candidate for low power consumption flexible non-volatile memory devices.