Since the development of the electronic transistor 60 years ago its technical utilization has revolutionized modern society. Consequent miniaturization was the key to this development. The challenge to develop flat printable electronics based on inorganic materials could give this area further input. It could be the basis for flexible displays or electronic paper when the active material is processable from solution, shows very good adherence to flexible substrates and excellent physical performance.[1] To meet these challenges any material considered requires a tuned set of functional properties. In general inorganic semiconductors are in advantage over organic materials as far as their physical performance is concerned. However, often processing and adherence to substrates is a problem with inorganic semiconductors. ZnO is available in various morphologies as transparent oxide, is non toxic, inexpensive and has shown promising physical semiconductor properties. [2][3][4] For solution processedZnO field-effect transistor (FET) devices, the highest electron mobility values are currently 1.65 cm 2 V À1 s À1 , however obtainable only after calcinations at temperatures >300 8C.[5] So far, despite promising physical performance parameters, neither synthesis conditions, nor processing techniques are yet compatible with existing printing technologies envisioned for flexible printing of ZnO semiconductors on polymer substrate basis. Currently the utmost challenge in the field is to gain a most complete understanding of the interplay between the parameters synthesis, processing and semiconductor performance for future development of printable electronic devices based on inorganic semiconductors such as ZnO. Despite a couple of recent reports on the deposition of zinc oxide thin layers in FET devices, processing from solution and conversion into the active FET channel electrode under fairly mild conditions is a great challenge. Chemical bath deposition techniques [6,7] and sol-gel processes were mainly investigated in this regard. [5,[8][9][10] However, both techniques typically require either high processing temperatures (above 300 8C) or long reaction times and are thus inappropriate for printing applications on flexible polymer based substrates under state of the art printing conditions. Processing temperatures well below 200 8C are the goal for the formation of semiconducting inorganic thin films onto such substrates. The application of soft processes like spin or dip coating or any kind of printing or stamping rely on the formation and adherence of such thin films on flexible substrates. Herein we report our investigations on the formation, characterization, low temperature processing and printing behavior of a molecular precursor and its conversion to unifom ZnO thin films and promising electronic performance of such films in an FET device.Our process starts from a modified synthesis of the ZnO single source precursor bis [2-(methoxyimino)propanoato]zinc 1 [11,12] (Scheme 1) which we developed for depositing thin tr...

The formation of nanoscale zinc oxide particles with an almost-monomodal size distribution synthesized by microwave heating of solutions of mononuclear zinc oximato or zinc acetylacetonato complexes in various alkoxyethanols is investigated. Transparent stable suspensions that contain these particles can be obtained from the zinc oximato precursor. Based on electron paramagnetic resonance (EPR) studies, a core/shell model with a finite surface shell thickness of 1.000 ± 0.025 nm is proposed for the ZnO nanoparticles. Field-effect transistor (FET) devices with these ZnO particles as the active semiconducting layer exhibited a charge carrier mobility of 0.045 cm2/(V s) and I on/off current ratios of ∼460.000, with a threshold voltage of 8.78 V.

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Nanostructured materials lie at the heart of fundamental advances in efficient energy storage and/or conversion, in which surface processes and transport kinetics play determining roles. This review describes recent developments in the synthesis and characterization of composites which consist of lithium metal phosphates (LiMPO(4), M = Fe, Co, Ni, Mn) coated on nanostructured carbon architectures (unordered and ordered carbon nanotubes, amorphous carbon, carbon foams). The major goal of this review is to highlight new progress in using different three dimensional nanostructured carbon architectures as support for the phosphate based cathode materials (e.g.: LiFePO(4), LiCoPO(4)) of high electronic conductivity to develop lithium batteries with high energy density, high rate capability and excellent cycling stability resulting from their huge surface area and short distance for mass and charge transport.

Electrochemical anodic oxidation of aluminium metal sheets leads to the formation of compact and dense, but highly porous alumina surfaces on top of the anode. The alumina surfaces obtained by anodic oxidation can be detached from the bare metal by using a voltage detachment procedure, without employing chemical etching techniques. This procedure leads to large area porous alumina membranes with closed backsides. Prestructuring of the aluminium base metal leads to ordered pore regions at anodisation voltages of 25, 40 and 50 V, resulting in porous alumina membranes with pore dia-

The influence of the composition within multilayered heterostructure oxide semiconductors has a critical impact on the performance of thin-film transistor (TFT) devices. The heterostructures, comprising alternating polycrystalline indium oxide and zinc oxide layers, are fabricated by a facile atomic layer deposition (ALD) process, enabling the tuning of its electrical properties by precisely controlling the thickness of the individual layers. This subsequently results in enhanced TFT performance for the optimized stacked architecture after mild thermal annealing at temperatures as low as 200 °C. Superior transistor characteristics, resulting in an average field-effect mobility (μ) of 9.3 cm V s ( W/ L = 500), an on/off ratio ( I/ I) of 5.3 × 10, and a subthreshold swing of 162 mV dec, combined with excellent long-term and bias stress stability are thus demonstrated. Moreover, the inherent semiconducting mechanism in such multilayered heterostructures can be conveniently tuned by controlling the thickness of the individual layers. Herein, devices comprising a higher InO/ZnO ratio, based on individual layer thicknesses, are predominantly governed by percolation conduction with temperature-independent charge carrier mobility. Careful adjustment of the individual oxide layer thicknesses in devices composed of stacked layers plays a vital role in the reduction of trap states, both interfacial and bulk, which consequently deteriorates the overall device performance. The findings enable an improved understanding of the correlation between TFT performance and the respective thin-film composition in ALD-based heterostructure oxides.

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What took so long? An ex situ investigation of an iron–aluminum nanocatalyst that is active in the water‐assisted growth of “super‐long” carbon nanotubes (CNTs) with different techniques (HRSTEM, EELS, XPS, GIXRD) reveals for the first time its bimetallic nature. Besides metallic aluminum and iron, mixed oxides, hydroxides, and aluminum oxycarbides play a role in the CNT growth process.