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Transistor Devices (transistor + device)

Distribution by Scientific Domains

Polymers and Materials Science	71%

Selected Abstracts

Solution-Processable Carbon Nanotubes for Semiconducting Thin-Film Transistor Devices

ADVANCED MATERIALS, Issue 11 2010
Chun Wei Lee
CoMoCat single-walled carbon nanotubes (SWNTs) treated with diazonium salts can be used to fabricate solution-processable field-effect transistors (FETs) with a full semiconductor device yield. By increasing the network thickness, the effective mobility of the devices can be raised to ,10 cm2 V,1 s,1 while keeping the on,off ratio higher than 5000. The removal of impurities is essential to achieve high-on,off-ratio devices. This approach is promising for preparation of SWNT inks for printing high-performance devices in flexible electronics. [source]

Special issue: Physics of Organic Semiconductors

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 6 2004
Wolfgang Brütting
This special issue of physica status solidi (a) gives an overview of our present-day knowledge of the physics behind organic semiconductor devices, ranging from the growth of organic layers and crystals, their electronic properties at interfaces, their photophysics and electrical transport properties to the application in organic field-effect transistors, photovoltaic cells and organic light-emit-ting diodes. Guest Editor of the present issue is Wolfgang Brütting, professor at the University of Augsburg, where he leads a research group working on organic semiconductors, their physical and materials properties, and the understanding of the basic processes in these materials and devices. The cover picture is an angular plot of the anisotropy of the charge carrier mobility , in the a,b plane of a rubrene single crystal, probed on an elastomeric rubber stamp field-effect transistor device. The black and red squares correspond to the values of , extracted from the linear and saturation regimes of the transistor operation, respectively. More information can be found in the Review Article by R. W. I. de Boer et al. [1]. [source]

Probing Biomolecular Interactions at Conductive and Semiconductive Surfaces by Impedance Spectroscopy: Routes to Impedimetric Immunosensors, DNA-Sensors, and Enzyme Biosensors

ELECTROANALYSIS, Issue 11 2003
Eugenii Katz
Abstract Impedance spectroscopy is a rapidly developing electrochemical technique for the characterization of biomaterial-functionalized electrodes and biocatalytic transformations at electrode surfaces, and specifically for the transduction of biosensing events at electrodes or field-effect transistor devices. The immobilization of biomaterials, e.g., enzymes, antigens/antibodies or DNA on electrodes or semiconductor surfaces alters the capacitance and interfacial electron transfer resistance of the conductive or semiconductive electrodes. Impedance spectroscopy allows analysis of interfacial changes originating from biorecognition events at electrode surfaces. Kinetics and mechanisms of electron transfer processes corresponding to biocatalytic reactions occurring at modified electrodes can be also derived from Faradaic impedance spectroscopy. Different immunosensors that use impedance measurements for the transduction of antigen-antibody complex formation on electronic transducers were developed. Similarly, DNA biosensors using impedance measurements as readout signals were developed. Amplified detection of the analyte DNA using Faradaic impedance spectroscopy was accomplished by the coupling of functionalized liposomes or by the association of biocatalytic conjugates to the sensing interface providing biocatalyzed precipitation of an insoluble product on the electrodes. The amplified detections of viral DNA and single-base mismatches in DNA were accomplished by similar methods. The changes of interfacial features of gate surfaces of field-effect transistors (FET) upon the formation of antigen-antibody complexes or assembly of protein arrays were probed by impedance measurements and specifically by transconductance measurements. Impedance spectroscopy was also applied to characterize enzyme-based biosensors. The reconstitution of apo-enzymes on cofactor-functionalized electrodes and the formation of cofactor-enzyme affinity complexes on electrodes were probed by Faradaic impedance spectroscopy. Also biocatalyzed reactions occurring on electrode surfaces were analyzed by impedance spectroscopy. The theoretical background of the different methods and their practical applications in analytical procedures were outlined in this article. [source]

Probing the Anisotropic Field-Effect Mobility of Solution-Deposited Dicyclohexyl-,-quaterthiophene Single Crystals,

ADVANCED FUNCTIONAL MATERIALS, Issue 10 2007

Abstract Measuring the anisotropy of the field-effect mobility provides insight into the correlation between molecular packing and charge transport in organic semiconductor materials. Single-crystal field-effect transistors are ideal tools to study intrinsic charge transport because of their high crystalline order and chemical purity. The anisotropy of the field effect mobility in organic single crystals has previously been studied by lamination of macroscopically large single crystals onto device substrates. Here, a technique is presented that allows probing of the mobility anisotropy even though only small crystals are available. Crystals of a soluble oligothiophene derivative are grown in bromobenzene and drop-cast onto substrates containing arrays of bottom-contact gold electrodes. Mobility anisotropy curves are recorded by measuring numerous single crystal transistor devices. Surprisingly, two mobility maxima occur at azimuths corresponding to both axes of the rectangular cyclohexyl-substituted quaterthiophene (CH4T) in-plane unit cell, in contrast to the expected tensorial behavior of the field effect mobility. [source]

Semiconducting Thienothiophene Copolymers: Design, Synthesis, Morphology, and Performance in Thin-Film Organic Transistors

ADVANCED MATERIALS, Issue 10-11 2009
Iain McCulloch
Abstract Organic semiconductors are emerging as a viable alternative to amorphous silicon in a range of thin-film transistor devices. With the possibility to formulate these p-type materials as inks and subsequently print into patterned devices, organic-based transistors offer significant commercial advantages for manufacture, with initial applications such as low performance displays and simple logic being envisaged. Previous limitations of both air stability and electrical performance are now being overcome with a range of both small molecule and polymer-based solution-processable materials, which achieve charge carrier mobilities in excess of 0.5,cm2 V,1 s,1, a benchmark value for amorphous silicon semiconductors. Polymer semiconductors based on thienothiophene copolymers have achieved amongst the highest charge carrier mobilities in solution-processed transistor devices. In this Progress Report, we evaluate the advances and limitations of this class of polymer in transistor devices. [source]

"Click" Dielectrics: Use of 1,3-Dipolar Cycloadditions to Generate Diverse Core-Shell Nanoparticle Structures with Applications to Flexible Electronics

MACROMOLECULAR RAPID COMMUNICATIONS, Issue 18 2008
Meghann A. White
Abstract We have synthesized a "universal ligand" incorporating a phosphonate surface anchor and a terminal alkyne moiety which binds to TiO2 nanoparticles and exhibits excellent dispersity in organic solvents. The alkyne functionality permits attachment of azide terminated polymer shells using "click" chemistry. Thus TiO2 core nanoparticles have been encapsulated with both polystyrene and poly(t -butyl acrylate) shells. The TiO2 -poly(t -butyl acrylate) core shell nanoparticles are amenable to further chemical transformation into TiO2 -poly(acrylic acid) nanoparticles through ester hydrolysis. These TiO2 -polyacrylic acid nanoparticles are dispersible in aqueous solution. The resulting core-shell nanoparticles have been incorporated as high K dielectric films in capacitor and organic thin film transistor devices and are promising new materials for flexible electronics applications. [source]