Design of High‐Mobility Diketopyrrolopyrrole‐Based π‐Conjugated Copolymers for Organic Thin‐Film Transistors

Since the report of the first diketopyrrolopyrrole (DPP)‐based polymer semiconductor, such polymers have received considerable attention as a promising candidate for high‐performance polymer semiconductors in organic thin‐film transistors (OTFTs). This Progress Report summarizes the advances in the molecular design of high‐mobility DPP‐based polymers reported in the last few years, especially focusing on the molecular design of these polymers in respect of tuning the backbone and side chains, and discussing the influences of structural modification of the backbone and side chains on the properties and device performance of corresponding DPP‐based polymers. This provides insights for the development of new and high‐mobility polymer semiconductors.     

Cover Picture: Direct Correlation of Organic Semiconductor Film Structure to Field‐Effect Mobility (Adv. Mater. 19/2005)

The use of near‐edge X‐ray absorption fine structure (NEXAFS) spectroscopy as a non‐destructive technique to quantify the simultaneous chemical conversion, molecular ordering, and defect formation of soluble oligothiophene precursor films intended for application in organic field‐effect transistors is demonstrated on p. 2340 by DeLongchamp and co‐workers. Illustrated from left to right, with increasing temperature: a) as‐cast, the molecules are weakly oriented; b) at the conversion onset, they become isotropic; c) after full conversion, they are strongly oriented and exhibit maximum field‐effect mobility; and d) overheating reduces film coverage and decreases their orientation, thus lowering their performance.