Preparation of wettability-controlled surface by electrostatic spray deposition to improve performance uniformity of small molecule/polymer blend organic field-effect transistors

Device-to-device variation of organic field-effect transistors (OFETs) hinders their path to integrated circuit applications due to anisotropic charge transport. In this study, blend solutions comprising 2-decyl-7-phenyl- (Smith et al., 2009) [1]benzothieno[3,2-b] (Smith et al., 2009) [1] benzothiophene (Ph-BTBT-10) as a semiconducting small-molecule and poly(methyl methacrylate) (PMMA) as an insulating polymer were electrosprayed onto lyophilic SiO2/Si substrates with patterned lyophobic fluoropolymer, which was also prepared by electrostatic spray deposition with a high-aspect-ratio shadow mask. Continuous blend films were only formed on elongated lyophilic regions, and vertical phase separation between Ph-BTBT-10 (top) and PMMA (bottom) was induced during the ESD process. The Ph-BTBT-10/PMMA blend OFETs with bottom-gate top-contact architecture fabricated on the elongated lyophilic regions exhibited improving performance uniformity.