Design of a Quinoidal Thieno[3,4‐b]thiophene‐Diketopyrrolopyrrole‐Based Small Molecule as n‐Type Semiconductor

A quinoidal small‐molecule semiconductor QDPPBTT was synthesized. Organic thin‐film transistor (OTFT) devices based on QDPPBTT showed an electron mobility as high as 0.13 cm2 V−1 s−1 and Ion/Ioff ratio of 106 under ambient conditions. We suggested that 2D extended π‐conjugation and quinoid‐enhancing effect had an important role in electron mobility and stability of n‐type FET devices, which might be a good strategy in designing new material systems.