Sinter-free inkjet-printed PEDOT:PSS/WO₃/PEDOT:PSS flexible valency change memory

Abstract

With the rapid proliferation of consumer electronics in our day to day lives, there is an ever increasing demand for flexible electronic devices which are low cost, easy to fabricate and deliver reliable performance. In this work, we report fabrication of symmetric poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS)/WO 3 /PEDOT:PSS memory cells by inkjet printing on transparent, flexible polyethylene naphthalate (PEN) substrates. The cells show resistive switching behavior with two stable resistance states. The current conduction across the interface between the PEDOT:PSS electrode and dielectric WO 3 is determined by localized filamentary features which is space charge limited in the high resistance state, facilitated through the migration of oxygen vacancies at low voltages (<2 V) whereas Schottky emission dominates the current conduction for higher voltages (>2 V). The cells show good retentivity and endurance (>6000 cycles). The cells are entirely sinter free and no electroforming is required to activate them. These characteristics make them suitable for the next generation of flexible non-volatile memory devices.

Mechanism of Oxygen Vacancy Filament-Based Resistive Switching in Non-polar Hf0.5Zr0.5O2-δ Thin Films

“…In this study, we consider three of the most commonly used conduction mechanisms for oxide materials: space-charge-limited conduction (SCLC), Poole–Frenkel, and Schottky emission. , As defects, specifically oxygen vacancies embedded in the Hf 0.5 Zr 0.5 O 2 – δ lattice, act as shallow traps, trapping and de-trapping provide an easy conduction pathway. Taking this into account, the first mechanism considered for fitting the HRS I – V curves is the space-charge-limited (SCLC) model, which is commonly used to explain the carrier migration process involved in resistive switching , and is strongly related to characteristic parameters of charge traps. The current density for SCLC can be written as follows …”

Fully printed ZnO-based valency-change memories for flexible and transparent applications

“…Due to the nature of the mechanism, high ON-OFF ratios have been achieved for the ZnO-based conductive bridge RAMs obtained by Sputtering, atomic layer deposition (ALD), pulsed laser deposition (PLD) and Sol-gel [21]. In an effort to explore how ZnO responds as the active material in a printed valency change ReRAM, we investigate the key performance parameters of these memory cells and report improved retention and endurance as compared to previously reported memories based on WO 3 [22].…”

“…Different oxide materials and semiconductors such as WO 3 [22], TiO 2 [23], ZrO [24], and CuO [25] have been used to fabricate ReRAM cells, and several studies have shown the attractive potential of oxide-based active layers for the memory. The design of printable and flexible cells make them remarkably interesting due to their low cost, safe use, high scalability, and unique electrical and mechanical properties.…”

Inkjet‐Printed Tungsten Oxide Memristor Displaying Non‐Volatile Memory and Neuromorphic Properties

“…This includes analog-type memristors to emulate biological synapses and neurons [16,17] and digital-type memristors for data storage applications. [18] Most of these devices are fabricated using advanced manufacturing methods, such as atomic layer deposition and magnetron sputtering, [16][17][18][19] but recently also printing of memristors is becoming more and more popular [20][21][22][23][24][25][26][27][28][29] Regarding printed electronics, digital printing technologies, such as electrohydrodynamic jet-, aerosol-, and inkjet-printing, are of particular interest due to their additive, material efficient, non-contact, and maskless fabrication capabilities. [30,31] Recent works on printed memristors mostly focus on digital-type memristors with filamentary type of resistive switching suitable for flexible or printed memory applications.…”