Investigation of Hole Transporting Properties in Thin-Film and Single-Crystal Organic Field-Effect Transistor Based on Dinaphtho[2,1-b:1',2'-d]thiophene

Abstract

We describe physicochemical properties, crystal structures, and field-effect transistor performances of dinaphtho[2,1-b:1',2'-d]thiophene (DNT-U) with a unique twisted structure. The HOMO energy level of DNT-U was estimated to be -5.77 eV by measurement of electrochemical property in solution, indicating that this material is a promising candidate for air-stable p-type organic semiconductors. DNT-U possesses anisotropic one-dimensional transfer integrals originating from the columnar face-to-face π-stacking motif, which was determined by X-ray single crystal structural analysis. In order to evaluate intrinsic hole transporting ability of DNT-U, we fabricated the single-crystal field-effect transistors (FETs). The devices showed hole mobility of up to 0.15 cm2 V-1 s-1, which value is almost one order of magnitude higher than that of the vacuum deposited thin film FETs.