Resistive Switching Behaviour of $\mathrm{PVP}/\mathrm{HfO}_{\mathrm{x}}$ Hybrid RRAM on Flexible Substrate

Abstract

Flexible devices have been in focus for their applications in wearable electronics, displays, sensors, and memory. $\mathrm{PVP}/\mathrm{HfO}_{\mathrm{x}}$ based hybrid resistive random access memory devices were demonstrated on flexible PET substrates to study their resistive switching characteristics and memory application. These RRAM devices exhibited decent repeatability of more than 100 cycles with excellent $I_{\mathrm{o}\mathrm{n}}/I_{\mathrm{off}}$ of ~106 at 0.2 V as read voltage. With retention time of more than 6000 s and reliable switching operation, the fabricated devices have potential to be embedded in flexible electronic applications. Moreover, conduction mechanism in devices was found to be ohmic at lower voltage levels in high resistance state (HRS) and space charge limited conduction at higher voltage levels, occurring mainly due to traps sites available in PVP and $\mathrm{HfO}_{\mathrm{x}}$ . The AFM image confirms the presence of pinholes at PVP surface which will eventually assist in filament formation.