Wafer-Scale, Highly Uniform Surface Functionalization from Vapor Phase and Applications to Organic Transistors

The surface functionalization by self-assembled monolayers (SAMs) favors well-packed organic semiconductor growth and reduces interfacial traps, which assists in developing high-performance organic thin-film transistors (OTFTs). Herein, the conventional SAM growth from the vapor phase is ameliorated and systematically studied. With 1H,1H,2H,2H-Perfluorodecyltrichlorosilane as an example, it is found that deposition temperature of no less than 120 °C and deposition pressure of up to 0.02 bar is preferred for SAM deposition without morphological defects. The optimized SAMs are ultrasmooth with a surface roughness of 0.09 nm and can be escalated to wafer scale. It is verified that the growth condition is universal for other trichlorosilane species. Finally, it is shown that the OTFTs with defect-free SAMs can achieve an average mobility of 1.79 cm Vs using dinaphtho(2,3-b:2′,3′-f)thieno(3,2-b)thiophene as the active layer, which is 2.06 times to the devices with defective SAMs and paces up the large-area and high-performance organic electronics.