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Printed ferroelectric devices are ideal candidates for self-powered and multifunctional sensor skins, contributing to a sustainable smart future.

Macroelectronic components combining different classes of devices often suffer from the high complexity and costs of the manufacturing processes. The printing of an active‐matrix sensor network using only five functional inks is demonstrated. The result is an all‐printed monolithically integrated touchless input interface, including ferroelectric sensor pixels, organic transistors for impedance matching, and an electrochromic display.

A mobility model for organic thin-film transistors (OTFTs) has been considered that fully accounts for the effect of grains and grain boundaries of the organic layer. The model has been applied to a top contact pentacene OTFT. Comparison between simulation results and experimental data shows a strong dependence of mobility as a function of grain size. The field-effect-extracted mobility is not linearly related to the grain size, but presents a rather abrupt reduction for a grain size smaller than 2 μm

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Based on the powerful concept of embedded dipole self‐assembled monolayers (SAMs), highly conductive interfacial layers are designed, which allow tuning the contact resistance of organic thin‐film transistors over three orders of magnitude with minimum values well below 1 kΩ cm. This not only permits the realization of highly competitive p‐type (pentacene‐based) devices on rigid as well as flexible substrates, but also enables the realization of n‐type (C60‐based) transistors with comparable characteristics utilizing the same electrode material (Au). As prototypical examples for the high potential of the presented SAMs in more complex device structures, flexible organic inverters with static gains of 220 V/V and a 5‐stage ring‐oscillator operated below 4 V with a stage frequency in the range of the theoretically achievable maximum are fabricated. Employing a variety of complementary experimental and modeling techniques, it is shown that contact resistances are reduced by i) eliminating the injection barrier through a suitable dipole orientation, and by ii) boosting the transmission of charge carriers through a deliberate reduction of the SAM thickness. Notably, the embedding of the dipolar group into the backbones of the SAM‐forming molecules allows exploiting their beneficial effects without modifying the growth of the active layer.

A monolithically integrated bifunctional frontplane is introduced to large area electronics. The bifunctional frontplane element is based on a composite foil of piezoelectric ceramic lead titanate nanoparticles embedded in a ferroelectric poly(vinylidene fluoride trifluoroethylene) polymer matrix. Bifunctionality to pressure and temperature changes is achieved by a sequential, area selective two-step poling process, where the polarization directions in the nanoparticles and the ferroelectric polymer are adjusted independently. Thereby, sensor elements that are only piezoelectric or only pyroelectric are achieved. The frontplane foil is overlaid on a thin-film transistor backplane. Our work constitutes a step toward multifunctional frontplanes for large area electronic surfaces.

We have fabricated a large body of pentacene thin films on different organic and inorganic dielectric materials at four substrate temperatures with different nominal film thicknesses ranging from the submonolayer over the multilayer to the "thick" film regime. These films were characterized by atomic force microscopy and analyzed quantitatively by means of scaling and rate equation theory in order to deduce the molecular growth dynamics of pentacene films on organic substrates that are used as gate dielectrics in organic thin film transistors. We found that on all substrates and in the substrate temperature range 25°C ഛ T s ഛ 70°C the growth can be well described as diffusion-limited aggregation. A critical island size of 3 ഛ i ഛ 4 was deduced from the scaling of the distribution density of the pentacene grain areas and the power-law dependence of the saturated nucleation density on the deposition rate. This is valid for all substrates in the investigated temperature regime and is also found to be true for 50 nm thick pentacene films thus emphasizing that the molecule-molecule interaction itself is independent of the underlying surface.