Small Molecule Semiconductors Based On Hemi-Isoindigo And Diketopyrrolopyrrole For Solution-Processed Organic Field-Effect Transistors

Two small semiconductor molecules based on diketopyrrolopyrrole (DPP) and hemi-isoindigo units with and without fluorination were designed and synthesized for investigating the solution-processed organic field-effect transistors (OFETs). Bottom-gate/top-contact (BG/TC) OFETs were fabricated to explore carrier transport characteristics. The combination of density functional theory (DFT) calculation, grazing incidence X-ray diffraction (GIXD), and atomic force microscopy (AFM) allowed us to understand the relationship between structures and properties. The results revealed the small molecule with fluorination (DPP-T-FMI) exhibited better field-effect performance owing to the improved crystal packing and morphology of thin-films.