Tunable p/n property of WS2 nanosheets-based ammonia gas sensor: Assembled by drop-coating and aerosol-jet printing

Transition metal dichalcogenides possess physical properties that are layer-dependent because of the adjustable band gap. Two dimensional WS2 shows room-temperature ammonia gas sensing property, while the sluggish response and recovery performance needs further improvement. The WS2-based ammonia gas sensor showed significant faster response and recovery property via aerosol-jet printing as compared to that of the dip-coating method results from the increased interlayer spacing of the WS2 nanosheets. Furthermore, the sensor's characteristics were changed from p-type to n-type through a simple aerosol-jet printing process because of the O and N doping introduced by the ultrasonic atomization and aerosol-jet printing. The aerosol-jet printing technology was demonstrated as a facile doping and assembling method that can change the p/n property of the WS2 nanosheets.