Highly Sensitive 2D TMDs Based NO2Gas Sensors via AACVD and APCVD Combination

In this work we report a new methodology for the direct growth, onto the sensor transducer, of multilayer transition metal dichalcogenides material (TMDs) such as tungsten diselenide (WSe2) and tungsten disulfide (WS2), via the combination of aerosol assisted chemical vapor deposition (AA-CVD) and atmospheric pressure CVD technique (APCVD). This combination led to uniform films with high yield and coverage, making it possible to overcome the shortcomings of many TMDs synthesis techniques. The morphology and the compositions of the films were investigated. The results revealed the formation of three dimensional (3D) assemblies of WSe2 nanosheets and WS2 nanotriangles. The fabricated sensors showed remarkable gas sensing performances towards 800 ppb of NO
2
at low operating temperature. Thanks to the vertical growth that enhanced the gas sensing performances by increasing the number of exposed edge as well as the number of defects.