Resistive switching characteristics of ZnO-graphene quantum dots and their use as an active component of an organic memory cell with one diode-one resistor architecture

摘要

We investigated the resistive switching characteristics of a polystyrene:ZnO-graphene quantum dots system and its potential application in a one diode-one resistor architecture of an organic memory cell. The log-log Ⅰ-Ⅴ plot and the temperature-variable Ⅰ-Ⅴ measurements revealed that the switching mechanism in a low-current state is closely related to thermally activated transport. The turn-on process was induced by a space-charge-limited current mechanism resulted from the ZnO-graphene quantum dots acting as charge trap sites, and charge transfer through filamentary path. The memory device with a diode presented a ～10~3 I_(ON)/I_(OFF) ratio, stable endurance cycles (10~2 cycles) and retention times (10~4 s), and uniform cell-to-cell switching. The one diode-one resistor architecture can effectively reduce cross-talk issue and realize a cross bar array as large as ～3 kbit in the readout margin estimation. Furthermore, a specific word was encoded using the standard ASCII character code.