Influence of inserting a thin fullerene layer on pentacene organic thin-film transistor

The performance of organic thin-film transistors (TFTs) with a pentacene/fullerene(C ₆₀)/pentacene (PCP) sandwich structure is presented. Using a 3.5 nm-thick C ₆₀ layer inserted between the pentacene films, the obtained hole mobility is improved by more than six times. By applying atomic force microscopy, x-ray diffraction, Raman spectrum, and transmission line method analysis, one can reasonably infer that the smoother surface of the pentacene film covered with thin C ₆₀ layer delays the phase transformation of the upper pentacene film, resulting in stronger intermolecular coupling and the reduction of channel resistance of the PCP TFTs from 3.03 to 1.72 M, and, therefore, improving the device performance.