Sputtered Deposited Cu Functionalized MoS₂ Nanoworm Thin Films for Nitrogen Dioxide (NO₂) Gas Sensor

Semiconducting nanostructures thin films are used in state-of-arts applications due to their heightened physical properties. Semiconducting metal sulfides nanostructures are a growing asset in current semiconductor technology due to their extraordinary physical, chemical, and electronic properties and their outstanding applications in different sensing and optoelectronic devices. The gas sensing capability of semiconducting nanostructures is a recent research interest of many researchers. The MoS 2 thin films were grown using reactive sputteringand the sensing performance of pure MoS 2 and Cu-MoS 2 thin films was studied towards nitrogen dioxide (NO 2 ) gas concentrations (2-200 ppm) at the optimum working temperature of 100℃. The Cu-MoS 2 sensor provides a high sensing response as compared to the pure MoS 2 thin-film sensor towards 20 ppm of NO 2 gas with a fast response and recovery time of 54 s and 82 s, respectively. It was observed that the proposed sensor chip displays an almost stable signal up to the 5 th cycle. It is observed that the proposed sensor device exhibits the highest response (30%) to NO 2 concerning weak response (10%) towards additional potentially interfering gases (NH 3 , CO, and H 2 ) at 100°C. It reveals that the Cu-MoS 2 thin-film sensor chip is highly selective to NO 2 gas at 100 °C.