Dinaphthotetrathiafulvalene Bisimides: A New Member of the Family of π‐Extended TTF Stable p‐Type Semiconductors

Air‐stable organic semiconductors based on tetrathiafuluvalene (TTF) were developed by synthesising a series of dinaphthotetrathiafulvalene bisimides (DNTTF‐Im) using electron‐donating TTF, π‐extended naphthalene, and electron‐withdrawing imide. Electron‐spin‐resonance spectroscopy and X‐ray single‐crystal structure analysis of aryl‐substituted DNTTF‐Im radical cations confirmed that localisation of the spin resides on the electron‐donating TTF moiety. The organic field‐effect transistor properties derived from the use of highly crystalline n‐butyl (C4) and n‐hexyl(C6)‐substituted DNTTF‐Im were assessed. The hole carrier mobility of C6‐DNTTF‐Im was improved from 3.7×10−3 cm2 V−1 s−1 to 0.30 cm2 V−1 s−1 in ambient conditions. This is attributed to the raise of the substrate temperature from 25 °C to 200 °C during sublimation. The XRD and microscopy analysis suggested that increasing the substrate temperature accelerates the end‐on packing resulting in larger grains suitable for hole charge transport parallel to the substrate. Stable p‐type semiconductors: Hole mobility as high as 0.3 cm2 V−1 s−1 in ambient condition was realized by a film of dinaphthotetrathiafulvalene bisimide by raise the substrate temperature to 200 °C during sublimation.