Rubrene Thin-film Transistors With Crystalline Channels Achieved On Optimally Modified Dielectric Surface

摘要

We report on the fabrication of rubrene thin-film transistors (TFTs) with surface-modified dielectrics adopting several kinds of self-assembled-monolayer (SAM) on SiO_2/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 SiO_2 dielectric showed quite a high field mobility of ～10~(-2) cm~2/Vs and a high on/off current ratio of ～10~5 under 40 V.