Ultrasensitive memristor-based gas sensor (gasistor) with gas-triggered switch and memory function for dilute NH3 detection

Accurately recording the time of toxic gas leakage is beneficial to find out the cause of the accident and evaluate the safety of the equipment. However, conventional gas sensors do not have the memory function without external storage devices. To develop gas sensors with both sensing and memory functions, memristor-based gas sensors have been proposed. The memristor-based gas sensors could be used as gas-triggered switch and gas sensors with a built-in memory, which was named gasistor. In this study, a TiO2-based gasistor was proposed for dilute NH3 detection at room temperature (RT). The gasistor displayed bipolar resistive switching behavior, excellent repeatability and stability. Gas-sensing measurements showed that TiO2-based gasistor could be used for ultrasensitive detection of NH3. The response to 1 ppm NH3 in the high resistance state (HRS) was as high as 164.2, and the response/recovery time was < 1 s, respectively. Especially, as the NH3 concentration decreased, the gasistor switched from the HRS to the low resistance state (LRS) and the NH3 leakage time was recorded. Based on the experimental results, we propose a more realistic gas-triggered switch mechanism model, which can be used to provide a reference for the prediction of gas-triggered voltage and compliance voltage.

Automated summary

A TiO2-based gasistor with bipolar resistive switching behavior was proposed for sensitive detection of NH3, showing excellent repeatability and stability. It can switch from a high resistance state to a low resistance state as the NH3 concentration decreases, recording the leakage time. The gasistor model provides a reference for predicting gas-triggered voltage and compliance voltage.