Highly transparent and flexible NO2 gas sensor film based on MoS2/rGO composites using soft lithographic patterning

Abstract

The MoS2/GO hybrid composite thin film is prepared by a facile solution mixing process. To reduce the composite film spin-coated on a SiO2 (300 nm)/Si substrate, thermal annealing at 600 °C for 1 h in a N2 atmosphere is used. The thermally reduced GO (rGO) composite film is subjected to line patterning through a soft lithographic patterning method, and the patterned MoS2/rGO composite thin film is re-transferred onto a PET film from the Si substrate. The patterned MoS2/rGO composite thin film has a thickness of about 10 nm and the transmittance of the patterned MoS2/rGO composite thin film on the PET substrate is 93%. The NO2 gas sensor device is fabricated and its basic characteristics are systematically investigated. The patterned MoS2/rGO composite thin film gas sensor has a sensitivity at least four times higher than the pure rGO thin film gas sensor. In addition, the characteristics of the sensor device are also maintained at a bending radius of 14 mm. This transparent and flexible patterned MoS2/rGO composite thin film can be used as a highly sensitive gas sensor that will detect a concentration as low as 0.15 ppm of harmful gases such as NO2.