"Dragging mode" electrohydrodynamic jet printing of polymer-wrapped semiconducting single-walled carbon nanotubes for NO gas-sensing field-effect transistors

In this study, we investigated facile "dragging mode" electrohydrodynamic (EHD) jet printing of a polymer-wrapped semiconducting single-walled carbon nanotube (s-SWCNT) ink, for fabrication of NO gas-sensing field-effect transistors (FETs). The "dragging mode" provides a favorable environment for reliable printing and interconnection between the s-SWCNTs. Printing parameters such as supply voltages, printing speeds, and the number of prints were manipulated to find an optimal printing condition and obtain high-performance FETs. Under optimal conditions, the polymer-wrapped s-SWCNT-based FETs exhibited an average field-effect mobility of 2.939 cm(2) (V-1 s(-1)), a threshold voltage of 2.21 V, an on/off ratio of similar to 10(3), and a subthreshold swing of 0.968 V dec(-1). Additionally, we demonstrated the application of FETs as NO sensors with high sensitivity and selectivity. The FET-type NO gas sensor exhibits a dynamic sensing range of 500 ppb-30 ppm and clear selectivity among various analyte gases including ethanol, ammonia, and acetone. Therefore, the "dragging mode" EHD jet printing introduced in this study simplifies patterning processes and is a potential reproducible method for the fabrication of next-generation gas sensors.