Realizing the Ultrafast Recovery of the Monolayer MoS2-Based NH3 Sensor by Gas-Ion-Gate

Over the past decade, the two-dimensional material MoS2 has attracted great attention due to its room temperature stability, high surface area-to-volume ratios, abundance of active sites at the edges, and exceptional surface sensitivity to the environment, which are key characteristics for applications in chemical sensing. However, the slow recovery of ammonia (NH3) sensors based on MoS2 materials at room temperature has restricted their further development. This paper presents a novel approach to address this limitation by demonstrating a monolayer MoS2-based NH3 sensor with rapid recovery capabilities, leveraging O2– generated through gas-ion-gate (GIG) technology. After being modulated by GIG, the recovery time of the monolayer MoS2 device is about 2.04 s, representing a substantial improvement─approximately 157 times faster than that without GIG modulation. The rapid recovery speed is attributed to the chemical interactions between the O2– ions generated by GIG and the surface-adsorbed NH3+, which expedite the rapid desorption of NH3+. Furthermore, the device retains periodic recovery properties, even after multiple modulation cycles, indicating that the material remains undamaged. This method successfully resolves the critical issue of slow recovery in monolayer MoS2-based NH3 sensors at room temperature.