High-performance solution-processed polymer ferroelectric field-effect transistors

We demonstrate a rewritable, non-volatile memory device with flexible plastic active layers deposited from solution. The memory device is a ferroelectric field-effect transistor (FeFET) made with a ferroelectric fluoropolymer and a bisalkoxy-substituted poly(p-phenylene vinylene) semiconductor material. The on- and off-state drain currents differ by several orders of magnitude, and have a long retention time, a high programming cycle endurance and short programming time. The remanent semiconductor surface charge density in the on- state has a high value of 18 mC m(-2), which explains the large on/off ratio. Application of a moderate gate field raises the surface charge to 26 mC m(-2), which is of a magnitude that is very difficult to obtain with conventional FETs because they are limited by dielectric breakdown of the gate insulator. In this way, the present ferroelectric-semiconductor interface extends the attainable field-effect band bending in organic semiconductors.</p

Morphology and conductivity of PEDOT/PSS films studied by scanning-tunneling microscopy

The influence of sorbitol on the nanometer-scale morphology of poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT/PSS) is investigated by scanning–tunneling microscopy. In all investigated films relatively well-conducting PEDOT particles are observed, with typical sizes of 10–50 nm, that are embedded in a less conductive PSS matrix. Addition of sorbitol to the casting solution is found to enhance the clustering of the PEDOT particles into larger domains. The observed morphologies are correlated to the macroscopic conductivity of the films, using an intuitive model. In addition, the morphology in the top layer of the films was found to differ substantially from the bulk morphology

Three-dimensional inhomogeneities in PEDOT:PSS Films

Spin-cast PEDOT/PSS film are investigated using scanning probe-based spectroscopic techniques. The films are found to consist of relatively well-conducting islands that are embedded in a less conductive matrix. A scanning-tunneling microscope-based method is developed to obtain three-dimensional conductivity images with nanometer resolution. Order-of-magnitude variations in the film conductivity are observed in all spatial directions. In addition, charge transport in the normal direction depends on the injection spot and is found to be ohmic or space-charge-limited. We found that both the morphology and the conductivity of the top layer differ substantially from those in the bulk, which is attributed to an enhanced PSS content in the top layer

Flexible electronic-paper active-matrix displays

\u3cp\u3eA 100-μm-thick 320 × 240-pixel active-matrix display integrated into a functional-device prototype is presented. The active matrix is composed of alternating layers of organic materials and gold. A six-mask photolithographic process is used. An electrophoretic electronic imaging film is laminated on top of the active matrix. The display is bendable to a radius of 7.5 mm for more than 30,000 repetitions.\u3c/p\u3

High-performance solution-processed polymer ferroelectric field-effect transistors

We demonstrate a rewritable, non-volatile memory device with flexible plastic active layers deposited from solution. The memory device is a ferroelectric field-effect transistor (FeFET) made with a ferroelectric fluoropolymer and a bisalkoxy-substituted poly(p-phenylene vinylene) semiconductor material. The on- and off-state drain currents differ by several orders of magnitude, and have a long retention time, a high programming cycle endurance and short programming time. The remanent semiconductor surface charge density in the on- state has a high value of 18 mC m(-2), which explains the large on/off ratio. Application of a moderate gate field raises the surface charge to 26 mC m(-2), which is of a magnitude that is very difficult to obtain with conventional FETs because they are limited by dielectric breakdown of the gate insulator. In this way, the present ferroelectric-semiconductor interface extends the attainable field-effect band bending in organic semiconductors

Rollable QVGA active-matrix displays based on organic electronics

\u3cp\u3eA 100μm thin QVGA active-matrix electrophoretic display is produced using organic transistors. The display can be bent to a radius less than 1 cm without any performance loss. Higher contrast and low crosstalk was achieved by addition of a field shield to our backplane\u3c/p\u3

High-performance solution-processed polymer ferroelectric field-effect transistors

We demonstrate a rewritable, non-volatile memory device with flexible plastic active layers deposited from solution. The memory device is a ferroelectric field-effect transistor (FeFET) made with a ferroelectric fluoropolymer and a bisalkoxy-substituted poly(p-phenylene vinylene) semiconductor material. The on- and off-state drain currents differ by several orders of magnitude, and have a long retention time, a high programming cycle endurance and short programming time. The remanent semiconductor surface charge density in the on-state has a high value of 18 mC m–2, which explains the large on/off ratio. Application of a moderate gate field raises the surface charge to 26 mC m–2, which is of a magnitude that is very difficult to obtain with conventional FETs because they are limited by dielectric breakdown of the gate insulator. In this way, the present ferroelectric–semiconductor interface extends the attainable field-effect band bending in organic semiconductors.