Origin of Hopping Conduction in Graphene-Oxide-Doped Silicon Oxide Resistance Random Access Memory Devices

In this letter, a double-active-layer
$({\rm Zr}{:}{\rm SiO}_{x}/{\rm C}{:}{\rm SiO}_{x})$
resistive switching memory device with a high on/off resistance ratio and small working current (0.02 mA), is presented. Through the analysis of Raman and Fourier transform infrared spectroscopy spectra, we find that graphene oxide exists in the
${\rm C}{:}{\rm SiO}_{x}$
layer. It can be observed that
${\rm Zr}{:}{\rm SiO}_{x}/{\rm C}{:}{\rm SiO}_{x}$
structure has superior switching performance and higher stability compared with the single-active-layer
$({\rm Zr}{:}{\rm SiO}_{x})$
structure, which is attributed to the existence of graphene oxide flakes formed during the sputter process.
$I-V$
characteristics under a series of increasing temperature were analyzed to testify the carrier hopping distance variation, which is further verified by our graphene oxide redox reaction model.