Gas-triggered resistive switching and chemiresistive gas sensor with intrinsic memristive memory

Combining gas sensing and resistive switching within a single device allows for its utilization as a gas sensor with built-in memory, capable of remembering a temporal change of the target gas concentration. In this work, coexistence of the hydrogen gas sensing and resistive switching in a capacitor-like Pt/TiO2/Pt structure is examined in detail. In particular, influence of the forming process on the sensor's response to hydrogen and influence of the hydrogen concentration on the resistive switching properties are studied. An equivalent device model based on the obtained data is proposed. The built-in memory operation, i.e. triggering the resistive switch by a change of the hydrogen gas concentration, is demonstrated for various devices at various temperatures and various humidity levels. It is shown that the response magnitude in the high resistance state (HRS) and variance of the voltage which triggers the set process are critical parameters for a reliable device operation.