Rubrene thin-film transistors with crystalline channels achieved on optimally modified dielectric surface

Abstract

We report on the fabrication of rubrene thin-film transistors (TFTs) with surface-modified dielectrics adopting several kinds of self-assembled-monolayer (SAM) on SiO2/P+-Si substrate. With the dielectric of lower surface energy, the crystalline rubrene growth or amorphous-to-crystalline transformation kinetics is faster during in-situ vacuum post-annealing, which was performed after rubrene vacuum deposition. In the present study, hexamethyldisilazane (HMDS) was finally determined to be the most effective SAM inter-layer for polycrystalline rubrene channel formation. Our rubrene TFT with HMDS-coated SiO2 dielectric showed quite a high field mobility of similar to 10(-2) cm(2)/V s and a high on/off current ratio of similar to 10(5) under 40V.