Micrometer‐Sized Organic Single Crystals, Anisotropic Transport, and Field‐Effect Transistors of a Fused‐Ring Thienoacene

Hexagonal micrometer-sized organic single crystals of a fused-ring thienoacene are grown controllably by physical vapor transport over a large area. A “two-dimensional organic-ribbon mask” technique is developed to fabricate organic field-effect transistors based on an individual microcrystal. The accomplished transistors exhibit mobility as high as 1.8 cm2V−1s−1 with on/off ratios of typically >107.