Enhancement of Memory Properties of Pentacene Field-Effect Transistor by the Reconstruction of an Inner Vertical Electric Field with an n-Type Semiconductor Interlayer

Organic field-effect transistors (OFETs) as nonvolatile memory units are essential for lightweight and flexible electronics, yet the practical application remains a great challenge. The positively charged defects in pentacene film at the interface between pentacene and polymer caused by environmental conditions, as revealed by theoretical and experimental research works, result in unacceptable high programming/erasing (P/E) gate voltages in pentacene OFETs with polymer charge-trapping dielectric. Here, we report a pentacene OFET in which an n-type semiconductor layer was intercalated between a polymer and a blocking insulator. In this structure, the hole barrier caused by the defect layer can be adjusted by the thickness and charge-carrier density of the n-type semiconductor interlayer based on the electrostatic induction theory. This idea was implemented in an OFET structure Cu/pentacene/poly(2-vinyl naphthalene) (PVN)/ZnO/SiO2/Si(p+), which shows low P/E gate voltages, large field-effect mobility (0.73 cm2 V-1 s-1), fast P/E speeds (responding to a pulse width of 5 × 10-4 s), and long retention time in air.