Mechanism of resistive switching in films based on partially fluorinated graphene

The mechanism of resistive switching in films of partially fluorinated graphene is investigated. The films are obtained on the basis of a number of graphene suspensions with different composition and various degree of fluorination. The dependence of the value of resistive switching on the presence of organic additives ($N$-methylpyrrolidone and dimethylformamide) in the suspension composition and the degree of fluorination are found experimentally. It is shown that, for films obtained from a suspension without organic components, no resistive switching is observed independently of the degree of fluorination. The most profound effect of $\sim$10–20 times is found for films containing dimethylformamide. A physical model for the films is proposed; according to this model, the dependence under observation is related to the presence of encapsulated functional groups formed from dimethylformamide molecules manifesting electrical activity in the investigated films. The measured current–voltage characteristics of the films are described in the best way by the Frenkel–Poole model with an activation energy of 0.08 eV of centers responsible for conduction. The value of switching depends on the degree of fluorination of the initial suspensions. The greatest effect is observed at a degree of fluorination of the suspensions of $\sim CF_{0.25}$. Suspensions of partially fluorinated graphene investigated in this study are suitable for fabricating device structures by the 2D-printing technology.