UV enhanced NO gas sensing properties of the MoS2 monolayer gas sensor

In recent days, 2-dimensional materials (2D) have become auspicious for gas sensor applications. Usually, the gas kinetics is poor at room temperature (RT). Considering the power consumption, photon excitation is an alternative way to enhance the gas kinetics at RT. In this work, we demonstrated the gas sensing properties of molybdenum disulfide (MoS2) monolayer at low temperature (RT ~ 27 °C to 100 °C). The monolayer MoS2 gas sensor has been developed using atomic-layered MoS2 synthesized by facile chemical vapor deposition (CVD), and structural properties were carried out by Raman spectroscopy. The NO gas was tested at three different operating temperatures (27 °C, 50 °C and 100 °C) and the effect of photonic energy on gas sensing performance at RT also manifested. The experimental results revealed that atomic MoS2 sensor exhibited a response of about 25% at RT, and improved response (70%) was observed to NO gas under UV light (λ = 254 nm). A large number of charge carriers perturbed on the surface of MoS2 under UV illumination, which could be contributed to enhance the response of the MoS2 sensor at RT.