Fluorosurfactant-Improved Wettability of Low-Viscosity Organic Semiconductor Solution on Hydrophobic Surfaces for High-Mobility Solution-Processed Organic Transistors

Abstract

Solution processibility is a unique superiority of organic semiconductors, which provides tremendous potential for the low-cost production of wearable and implantable electronics. However, the solution affinity to the substrate surface remains a serious dilemma due to the difficulty of liquid manipulation on hydrophobic surfaces, but the use of such surfaces is essential to improve device performance. Here, we applied a new-type additive, non-ionic fluorosurfactant, to add into the organic semiconductor solution. It not only can effectively improve the wettability of the low-viscosity solution on the hydrophobic surface, but also enhance the field-effect performance of the fabricated poly[4-(4,4-dihexadecyl-4H-cyclopenta[1,2-b:5,4-b']dithophen-2-yl)-alt-[1, 2, 5]- thiadiazolo[3,4-c]pyridine] organic thin-film transistors (OTFTs) by forming vertical phase separation. Combined with the nanogrooved octadecyltrichlorosilane/SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , the obtained OTFTs exhibit excellent field-effect characteristics with mobility as high as 4.02 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> V <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> s <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> , which far surpasses that of modern industrial amorphous silicon. This work provides a simple strategy to prepare continuous and uniform organic semiconductor thin film on the hydrophobic surface, indicating promising potential for future high-performance solution-processed organic electronic devices.