Volatile and nonvolatile resistive switching reconfiguration in CeO2-based memristor

The era of big data and the rapid development of artificial intelligence pose urgent demand on reconfigurability of memristive devices. Here, we demonstrate that a Pt/CeO2/V memristor can exhibit both nonvolatile and volatile characteristics through voltage polarity control and operation sequence. Nonvolatile switching is obtained by applying a positive sweep followed by a negative sweep, whereas volatile switching arises from consecutive positive sweeps. Notably, the device shows excellent performance in both operation modes. As a nonvolatile memory, it exhibits low coefficient of variation of set/reset voltage (17%), robust retention time (∼105 s), and stable on/off ratio (∼10). As a volatile memory, it displays low operation voltage (∼0.9 V), ultrahigh uniformity (∼1%), and high selectivity over 102. It is supposed that these behaviors can be attributed to polarity-dependent filament dynamics: negative bias induces filament rupture in the CeO2 layer, while positive bias governs filament formation and rupture in the VOx layer. This study is helpful for the development of CeO2-based memristive devices with configurable functionalities.