Mechanically flexible low-leakage multilayer gate dielectrics for flexible organic thin film transistors

The incorporation of an ultrathin, atomic layer deposited HfO₂ layer in between the spin-coated poly-4-vinyl phenol (PVP) organic layers in the laminated multilayer gate dielectric for pentacene organic thin film transistors on a flexible substrate reduced the gate leakage current by three to four orders of magnitude and thereby significantly enhanced the current on/off ratio up to ≅10⁴-fold. Cyclic bending testing indicated that the electrical characteristics of the device with the PVP/HfO₂/PVP trilayer gate dielectric stack were superior to those of the device with the single PVP gate dielectrics due to the improved mechanical and electrical stabilities of the gate dielectric.