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 degrees 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(2) V(-1)s(-1) 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.

Automated summary

The surface functionalization using self-assembled monolayers (SAMs) improves the growth of organic semiconductors and reduces interfacial traps, leading to high-performance organic thin-film transistors (OTFTs). By optimizing the deposition conditions, it is found that SAMs deposited from vapor phase at a temperature of 120 degrees C and pressure of 0.02 bar exhibit no morphological defects. The defect-free SAMs show ultrasmooth surfaces and can be scaled up to wafer size. OTFTs with defect-free SAMs achieve an average mobility of 1.79 cm(2) V(-1)s(-1), outperforming devices with defective SAMs and advancing large-area and high-performance organic electronics.