Y6 Organic Thin‐Film Transistors with Electron Mobilities of 2.4 cm(2) V(−1) s(−1) via Microstructural Tuning

There is a growing demand to attain organic materials with high electron mobility, μ (e), as current reliable reported values are significantly lower than those exhibited by their hole mobility counterparts. Here, it is shown that a well‐known nonfullerene‐acceptor commonly used in organic solar cells, that is, BTP‐4F (aka Y6), enables solution‐processed organic thin‐film transistors (OTFT) with a μ (e) as high as 2.4 cm(2) V(−1) s(−1). This value is comparable to those of state‐of‐the‐art n‐type OTFTs, opening up a plethora of new possibilities for this class of materials in the field of organic electronics. Such efficient charge transport is linked to a readily achievable highly ordered crystalline phase, whose peculiar structural properties are thoroughly discussed. This work proves that structurally ordered nonfullerene acceptors can exhibit intrinsically high mobility and introduces a new approach in the quest of high μ (e) organic materials, as well as new guidelines for future materials design.