Solution‐Processable Route for Large‐Area Uniform 2D Semiconductor Nanofilms

Abstract The semiconductor thin film engineering technique plays a key role in the development of advanced electronics. Printing uniform nanofilms on freeform surfaces with high efficiency and low cost is significant for actual industrialization in electronics. Herein, a high‐throughput colloidal printing (HTCP) strategy is reported for fabricating large‐area and uniform semiconductor nanofilms on freeform surfaces. High‐throughput and uniform printing rely on the balance of atomization and evaporation, as well as the introduced thermal Marangoni flows of colloidal dispersion, that suppresses outward capillary flows. Colloidal printing with in situ heating enables the fast fabrication of large‐area semiconductor nanofilms on freeform surfaces, such as SiO 2 /Si, Al 2 O 3 , quartz glass, poly(ethylene terephthalate) (PET), Al foil, plastic tube, and Ni foam, expanding their technological applications where substrates are essential. The printed SnS 2 nanofilms are integrated into thin‐film semiconductor gas sensors with one of the fastest responses (8 s) while maintaining the highest sensitivity ( R g /R a = 21) (toward 10 ppm NO 2 ), as well as an ultralow limit of detection (LOD) of 46 ppt. The ability to print uniform semiconductor nanofilms on freeform surfaces with high‐throughput promises the development of next‐generation electronics with low cost and high efficiency.