Search results for "Transistor"
showing 10 items of 234 documents
Anodized Ti-Si Alloy as Gate Oxide of Electrochemically-Fabricated Organic Field-Effect Transistors
2013
Organic field-effect transistors were fabricated using an electrochemical route. The dielectric oxide was grown by anodization of a Ti:Si alloy, while 3,4-polyethylenedioxythiophene has been employed as a semiconducting polymer. OutputI-Vcharacteristics showed a transistor effect dependent on dielectric thickness. Fitting between I-V measurements and theoretical simulations in the triode region confirmed the presence of a conduction path through the polymer which degrades the electrical characteristics of the devices.
Humidity Insensitive Conductometric Sensors for Ammonia Sensing
2014
Interest in molecular materials has been driven in large part by their various and prosperous applications, especially in the domain of organic electronics, where they offer many advantages as well as alternative approaches compared to their inorganic counterparts. Most of conductometric transducers are resistors[[ and transistors[[[, but rarely diodes[6]. In our laboratory, we designed and characterized new molecular material based devices. Molecular Semiconductor Doped Insulator (MSDI) heterojunctions were built around a heterojunction between a Molecular Semiconductor (MS) and a Doped Insulator (DI)[7][8]. This new device exhibits interesting electronic properties that allow ammonia sens…
Electrochemical fabrication of metal/oxide/conducting polymer junction
2011
After discovery of conducting polymers and the possibility to modify their electrical properties from insulating to metallic like behavior by doping and a careful choice of the processing conditions, a large amount of research effort has been devoted to the theoretical understanding of their solid state properties as well as to exploit the possible application of conducting polymers in many technological fields including large area organic electronics, polymer photovoltaic cell, and sensors. 1-4 Organic thin film transistors appear very promising devices for the development of low cost, flexible, and disposable plastic electronics. In order to reduce the operating voltage it has been sugges…
Recent advances in upscalable wet methods and ink formulations for printed electronics
2014
This review deals with the use of solution processing approaches for organic electronics with a focus on material ink formulations as well as on their applicability. The solution processing techniques include methods like gravure printing, screen printing and ink-jet printing. Basic principles of each approach are understood and fundamental correlations between material (metals, semiconductors, and dielectrics) ink properties and final device performances can be drawn. Nevertheless, solution processing methods have the potential to evolve as the most promising tools in organic device fabrication techniques and have already been applied successfully in the fields of organic thin film transis…
Organic Thin-Film Transistors with Enhanced Sensing Capabilities
2009
Organic thin-film transistors, used as sensing devices, have been attracting quite a considerable interest lately as they offer advantages such as multi parameter behaviour and possibility to be quite easily molecularly tuned for the detection of specific analytes. Here, a study on the dependences of the devices responses on important parameters such as the active layer thickness and its morphology as well as on the transistor channel length is presented. To introduce the least number of variables the system chosen for this study is quite a simple and well assessed one being based on a thiophene oligomer active layer exposed to 1-butanol vapours.
Determination of charge carrier mobility of hole transporting polytriarylamine-based diodes
2010
Hole transport properties of three different side chain poly(triarylamines) have been determined by means of the analysis of steady-state current-voltage characteristics using co-planar diode structures. The interpretation is based on space-charge limited models with field-dependent mobility. Mobilities between ~ 10- 8 and 10- 6 cm2 V- 1 s- 1 are obtained. The highest mobility is achieved for poly(tetraphenylbenzidine) devices and the lowest for poly(triphenylamine) devices. Electron-rich methoxy substituents increase the mobility of poly(triphenylamine)s. A comparison of the mobility values with those obtained using organic field-effect transistors is also given. © 2009 Elsevier B.V. All r…
Current status of AlInN layers lattice-matched to GaN for photonics and electronics
2007
We report on the current properties of Al1-x InxN (x approximate to 0.18) layers lattice- matched ( LM) to GaN and their specific use to realize nearly strain- free structures for photonic and electronic applications. Following a literature survey of the general properties of AlInN layers, structural and optical properties of thin state- of- the- art AlInN layers LM to GaN are described showing that despite improved structural properties these layers are still characterized by a typical background donor concentration of ( 1 - 5) x 10(18) cm(-3) and a large Stokes shift (similar to 800 meV) between luminescence and absorption edge. The use of these AlInN layers LM to GaN is then exemplified …
First results from electrical qualification measurements on DEPFET pixel detector
2010
We report on the first results from a new setup for electrical qualification measurements of DEPFET pixel detector matrices. In order to measure the transistor properties of all pixels, the DEPFET device is placed into a benchtest setup and electrically contacted via a probecard. Using a switch matrix, each pixel of the detector array can be addressed individually for characterization. These measurements facilitate to pre-select the best DEPFET matrices as detector device prior to the mounting of the matrix and allow to investigate topics like the homogeneity of transistor parameters on device, wafer and batch level in order to learn about the stability and reproducibility of the production…
Measuring charge based quantum bits by a superconducting single-electron transistor
2002
Single-electron transistors have been proposed to be used as a read-out device for Cooper pair charge qubits. Here we show that a coupled superconducting transistor at a threshold voltage is much more effective in measuring the state of a qubit than a normal-metal transistor at the same voltage range. The effect of the superconducting gap is to completely block the current through the transistor when the qubit is in the logical state 1, compared to the mere diminishment of the current in the normal-metal case. The time evolution of the system is solved when the measuring device is driven out of equilibrium and the setting is analysed numerically for parameters accessible by lithographic alu…
Ground-state spin blockade in a single-molecule junction
2019
It is known that the quantum mechanical ground state of a nanoscale junction has a significant impact on its electrical transport properties. This becomes particularly important in transistors consisting of a single molecule. Because of strong electron-electron interactions and the possibility of accessing ground states with high spins, these systems are eligible hosts of a current-blockade phenomenon called a ground-state spin blockade. This effect arises from the inability of a charge carrier to account for the spin difference required to enter the junction, as that process would violate the spin selection rules. Here, we present a direct experimental demonstration of a ground-state spin …