Pentacene thin-film transistor with PVP-capped high-k MgO dielectric grown by reactive evaporation

Abstract

Pentacene thin-film transistors operated at low voltages have been realized by employing hybrid dielectrics, poly(4-vinylphenol) (PVP)-capped MgO. The MgO film was deposited by reactive evaporation of magnesium in oxygen. The PVP layer plays a role in modifying the surface morphology of the MgO layer, and the images of atomic force microscopy for the PVP-capped MgO films show a root-mean-square roughness of 1 nm. The hybrid dielectric has a dielectric constant of 7.05 with a dielectric strength. The fabricated pentacene organic thin-film transistors exhibit a mobility of 0.66 cm(2)/V s, a threshold voltage of -2.67 V, and an on/off ratio of 10(3). (c) 2008 The Electrochemical Society.