Oxidized carbon quantum dot–graphene oxide nanocomposites for improving data retention of resistive switching memory

Abstract

Data retention of nano-sized conducting filaments is a critical reliability issue in the pursuit of low-power graphene oxide-based resistive switching (RS) memory devices. Herein, an improvement in the low resistance state retention is demonstrated in fabricated oxidized carbon quantum dot (OCQD)–graphene oxide nanocomposites. Reliable RS characteristics with good retention properties were achieved instead of volatile switching, even with a relatively low compliance current of 100 μA. More epoxy groups were introduced as the concentration of embedded OCQDs was increased, resulting in a larger high resistance state, a higher set voltage, and deeper trapping levels. The dependence of the set switching time on the temperature acts as experimental verification that the oxygen migration energy barrier E_a was improved from 0.37 to 0.78 eV after embedding the OCQDs, which explains the enhancement of the low resistance state retention based on a filamentary model.