Resistance switching characteristics of Ag/ZnO/graphene resistive random access memory

In this work, an Ag/ZnO/Graphene structure resistive random access memory (RRAM) is prepared through RF magnetron sputtering. Compared to the Ag/ZnO/Au structure device, the endurance of the device using a graphene electrode up to 3 × 103 cycles. It has a self-current compliance function of 2 × 10−4 A and 30 times switching resistance ratio and characteristics without electroforming. The density of states (DOS) of ZnO supercells with different space groups are calculated by using the first-principles, and it is analyzed that the contributions of different supercells to the conductivity and contact type of the RRAM. Combined with the I–V curve of the RRAM, it illustrated that the conduction path is created by the space-charge-limited conduction (SCLC) of electrons captured by oxygen vacancy traps. The biocompatibility of the device is tested by a cell toxicity test. It proves that the Ag/ZnO/Graphene RRAM has high biocompatibility and broad applicability in implantable biomedical devices.