Diketopyrrolopyrrole-Containing Quinoidal Small Molecules for High-Performance, Air-Stable, and Solution-Processable n-Channel Organic Field-Effect Transistors

We report the synthesis, characterization, and application
of a
novel series of diketopyrrolopyrrole (DPP)-containing quinoidal small
molecules as highly efficient n-type organic semiconductors in thin
film transistors (TFTs). The first two representatives of these species
exhibit maximum electron mobility up to 0.55 cm2 V–1 s–1 with current on/current off
(Ion/Ioff)
values of 106 for 1 by vapor evaporation,
and 0.35 cm2 V–1 s–1 with Ion/Ioff values of 105–106 for 2 by solution process in air, which is the first demonstration of
DPP-based small molecules offering only electron transport characteristics
in TFT devices. The results indicate that incorporation of a DPP moiety
to construct quinoidal architecture is an effective approach to enhance
the charge-transport capability.