Monopolar Resistive Switching in Diamond-Like Carbon Films

Current–voltage characteristics were studied for Pt/diamond-like C/Pt structures based on thin (20 nm) diamond-like carbon films, when the ratio between carbon phases with sp2 and sp3 hybridization was controlled by the film growth conditions at the high-frequency diode sputtering method. The effects of resistive switching from the initial high-resistive state to a low-resistive state at an applied voltage of V ~ 3 V and reverse switching at V ~ 0 are detected. These effects are symmetric with respect to change in voltage polarity and are associated with the change in the hybridization type of local carbon regions, which causes switching from the high- to low-resistive state in strong (~106 V/cm) fields because of sp3 → sp2 transitions and reverse switching in the field absence. The high-to-low resistance ratio reaches ~50.