Impact of p-type doping on charge transport in blade-coated small-molecule:polymer blend transistors

Blade-coating is a roll-to-roll (R2R) compatible processing technique and has the potential to address the industry's needs for scalable manufacturing of future organic electronics. Here we investigate the applicability of blade-coating for the fabrication of organic thin-film transistors (OTFTs) based on best-in-class organic semiconducting blends comprised of the conjugated small-molecule 2,7-dioctyl[1]benzothieno[3,2- b ][1]benzothiophene (C 8 -BTBT), and the conjugated polymer poly(indacenodithiophene- co -benzothiadiazole) (C 16 IDT-BT). We show that the operating characteristics of blade-coated transistors consistently outperform devices prepared via spin-coating, showcasing the compatibility of the technique. Introducing the molecular p-dopant C 60 F 48 into the binary C 8 -BTBT:C 16 IDT-BT blend formulation, in combination with carefully optimized blade-coating conditions, helps to enhance the performance of the ensuing transistors further resulting in a maximum hole mobility of 14 cm 2 V −1 s −1 , and an all-around improvement of the device operating characteristics. Our results show that p-doped blend OTFTs can be manufactured using industry relevant processing techniques without sacrificing their state-of-the-art performance. Blade-coating is used to fabricate high hole mobility organic transistors based on a p-doped small-molecule:polymer blend semiconductor.