A multifunctional memristor with coexistence of NDR and RS behaviors for logic operation and somatosensory temperature sensing applications

The negative differential resistance (NDR) effect has been widely applied in logic circuits, wireless communications, and neural networks, but the study for the coexistence of NDR and resistance switching (RS) behaviors is still in the initial stage. In this work, a memristive device with an Ag/ZnO_x/TiO_y/indium tin oxide (ITO) structure was fabricated, and the device exhibits coexistence of RS and NDR behaviors with the change of applied voltages at air environment. Further, the stable and controllable coexistence of RS and NDR behaviors can be achieved in the memristive device under extreme environments. In addition, the multifunctional applications of the as-prepared memristor based on the coexistence of RS and NDR behaviors in logic operation and somatosensory temperature sensing were also demonstrated. Finally, based on the in-depth analysis of the experimental data and the energy band theory, the physical models of water molecule (H₂O) decomposition, oxygen vacancy (V_o²⁺), Ag ions (Ag⁺), and hydroxide ions (OH^–) migration were proposed, which reasonably explained the working mechanism of the coexistence of RS and NDR behaviors. Therefore, this work proves that the coexistence behavior of NDR and RS behaviors controlled by multiple factors in memristor has great application prospects for logic operation and somatosensory temperature sensing.