Fullerene-derivative as interlayer for high performance organic thin-film transistors

Abstract

In this paper, a novel fullerene-naphthalenediimide derivative (abbreviated as C₆₀-NDI) was synthesized and used as an interlayer in pentacene transistors. We found that a significant improvement was achieved with C₆₀-NDI as an interlayer between the pentacene active layer and the gate dielectric. The highest field-effect mobility and on/off current ratio approached 1.76 cm² V⁻¹ s⁻¹ and 10⁸, respectively, which is even higher than those of devices under the same experimental conditions fabricated on conventional SAMs (such as octadecylsilanes (OTS) and hexamethylene disilazane (HMDS)) treated substrates. Further investigations carried out by contact angle tests, atomic force microscopy, X-ray diffraction, and Raman spectroscopy demonstrated that the formation of large grain sizes, high crystallinity, and good grain interconnectivity for pentacene thin films on a C₆₀-NDI surface leads to high device performance, suggesting its application as a new interface engineering species for modifying the gate dielectric to improve device performance.