Highly sensitive detection of NO2 at room temperature using thin-film transistor gas sensor based on MoS2/ZnO composites

Abstract NO 2 detection is crucial for air quality monitoring and pollution control, yet achieving fast and highly sensitive detection of NO 2 at low temperatures remains challenging. Herein, a room-temperature (RT) NO 2 gas sensor is developed based on a thin-film transistor (TFT) structure with a MoS 2 /ZnO composite as both the channel and sensing layer. The NO 2 sensing performance of the sensor was evaluated at RT under UV illumination. It was found that the MoS 2 /ZnO sensor exhibited a 72.9% response to 500 ppb NO 2 , approximately 1.24 times higher than that of pristine ZnO, along with rapid response/recovery times of 40 s and 50 s, respectively. The improved NO 2 -sensing performance can be attributed to the formation of the MoS 2 /ZnO p-n heterojunction, which facilitates efficient charge separation and transfer via the built-in electric field. Additionally, the two-dimensional layered structure of MoS 2 improves the dispersion of ZnO nanoparticles, promoting gas-solid contact and enhancing the interaction with NO 2 molecules. This work demonstrates the feasibility of achieving high-sensitivity NO 2 detection at RT, with great potential for next-generation IoT-enabled environmental monitoring systems.