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Author

Wolfgang H. Krautschneider

Other affiliations: University of Hamburg
Bio: Wolfgang H. Krautschneider is an academic researcher from Hamburg University of Technology. The author has contributed to research in topics: CMOS & Gate oxide. The author has an hindex of 18, co-authored 116 publications receiving 1002 citations. Previous affiliations of Wolfgang H. Krautschneider include University of Hamburg.


Papers
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Journal ArticleDOI
TL;DR: In this article, the authors investigated hysteresis in pentacene-based field effect transistors with SiO2 as gate dielectric and showed that hole trapping is responsible.
Abstract: We have investigated hysteresis in pentacene-based field-effect transistors with SiO2 as gate dielectric. A clear hysteresis behavior in transfer and output characteristics is reported. Measurements show that the observed hysteresis is due to hole trapping in the pentacene film. Long time constants of the trapping/detrapping mechanism are demonstrated through transient measurements. An initialization routine to be performed prior to measurements is proposed to enable reproducible and reliable measurements on pentacene transistors.

77 citations

Journal ArticleDOI
TL;DR: In this article, a solution-processed composite film based on poly(vinylidene fluoride/trifluoroethylene) copolymer and barium titanate (BT) nanopowder was used as ferroelectric high-κ gate insulation in organic field effect transistors (OFETs).
Abstract: The authors report on a solution-processed composite film based on poly(vinylidene fluoride/trifluoroethylene) copolymer and barium titanate (BT) nanopowder, to be used as ferroelectric high-κ gate insulation in organic field-effect transistors (OFETs) Flexible films of up to 50vol% BT powder content are produced by preparing homogeneous dispersion of the powder in the polymer solutions The films exhibited high specific volume resistivities combined with dielectric constants of up to 515 at 1kHz Low-voltage OFETs with ferroelectric hysteresis and good memory retention properties were demonstrated by using the composite films

73 citations

Journal ArticleDOI
TL;DR: In this article, the relationship between HfO2 crystalline phase and the resulting electrical properties was investigated and a 10% SiO2 mixture was used to avoid formation of local defects by stabilization of the tetragonal phase and concurrently increased the permittivity.
Abstract: The authors report the relationship between HfO2 crystalline phase and the resulting electrical properties. Crystallization of amorphous HfO2 into the monoclinic phase led to a significant increase in leakage current and formation of local defects. Admixture of 10% SiO2 avoided formation of these defects by stabilization of the tetragonal phase, and concurrently increased the permittivity to 35. This understanding enabled fabrication of crystalline HfO2 based metal-insulator-metal capacitors able to withstand a thermal budget of 1000°C while optimizing capacitance equivalent thickness (<1.3nm) at low leakage [J(1V)<10−7A∕cm2].

70 citations

Journal ArticleDOI
TL;DR: The EMG recorded during goal-directed arm movements showed a high similarity to movements in the same direction and at the same time presented clear differences between different movement directions in time domain, which led to reliable recognition of arm movements.
Abstract: This paper presents intramuscular electromyogram (EMG) signals obtained with a fully implantable measurement system that were recorded during goal directed arm movements. In a first implantation thin film electrodes were epimysially implanted on the deltoideus of a rhesus macaque and the encapsulation process was monitored by impedance measurements. Increase of impedance reached a constant level after four weeks indicating a complete encapsulation of electrodes. EMG recorded with these electrodes yielded a signal-to-noise ratio of about 80 dB at 200 Hz. The EMG recorded during goal-directed arm movements showed a high similarity to movements in the same direction and at the same time presented clear differences between different movement directions in time domain. Six classifiers and seven time and frequency domain features were investigated with the aim of discriminating the direction of arm movement from EMG signals. Reliable recognition of arm movements was achieved for a subset of the movements under investigation only. A second implantation of the whole measurement system for nine weeks demonstrated simple handling during surgery and good biotolerance in the animals.

46 citations

Journal ArticleDOI
TL;DR: A system-on-chip (SoC) that combines multiple biomedical signal acquisition (ECG, EEG, EP, and respiration-related signals) with on-chip digital signal processing is presented and the embedded flexibility of the SoC facilitates its use in a multitude of applications.
Abstract: In this paper, a system-on-chip (SoC) that combines multiple biomedical signal acquisition (ECG, EEG, EP, and respiration-related signals) with on-chip digital signal processing is presented The embedded flexibility of the SoC facilitates its use in a multitude of applications Time-sharing of the operational transconductance amplifier within the analog-to-digital converters is employed in order to lower the power consumption and to save area Built-in self-test (BIST) and autocalibration capabilities are included to enhance its reliability The low noise analog front-end (AFE) is fully programmable to achieve the best power-noise trade-off for the application at hand A prototype has been manufactured in 035 μm 33 V CMOS technology

45 citations


Cited by
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Journal ArticleDOI
TL;DR: This review suggests that organic phototransistors have a large potential to be used in a variety of optoelectronic peculiar applications, such as a photo-sensor, opto-isolator, image sensor, optically controlled phase shifter, and opto -electronic switch and memory.
Abstract: While organic electronics is mostly dominated by light-emitting diodes, photovoltaic cells and transistors, optoelectronics properties peculiar to organic semiconductors make them interesting candidates for the development of innovative and disruptive applications also in the field of light signal detection. In fact, organic-based photoactive media combine effective light absorption in the region of the spectrum from ultraviolet to near-infrared with good photogeneration yield and low-temperature processability over large areas and on virtually every substrate, which might enable innovative optoelectronic systems to be targeted for instance in the field of imaging, optical communications or biomedical sensing. In this review, after a brief resume of photogeneration basics and of devices operation mechanisms, we offer a broad overview of recent progress in the field, focusing on photodiodes and phototransistors. As to the former device category, very interesting values for figures of merit such as photoconversion efficiency, speed and minimum detectable signal level have been attained, and even though the simultaneous optimization of all these relevant parameters is demonstrated in a limited number of papers, real applications are within reach for this technology, as it is testified by the increasing number of realizations going beyond the single-device level and tackling more complex optoelectronic systems. As to phototransistors, a more recent subject of study in the framework of organic electronics, despite a broad distribution in the reported performances, best photoresponsivities outperform amorphous silicon-based devices. This suggests that organic phototransistors have a large potential to be used in a variety of optoelectronic peculiar applications, such as a photo-sensor, opto-isolator, image sensor, optically controlled phase shifter, and opto-electronic switch and memory.

1,081 citations

01 Jan 2016
TL;DR: The design of analog cmos integrated circuits is universally compatible with any devices to read and is available in the book collection an online access to it is set as public so you can download it instantly.
Abstract: Thank you for downloading design of analog cmos integrated circuits. Maybe you have knowledge that, people have look hundreds times for their chosen books like this design of analog cmos integrated circuits, but end up in malicious downloads. Rather than enjoying a good book with a cup of coffee in the afternoon, instead they juggled with some harmful virus inside their computer. design of analog cmos integrated circuits is available in our book collection an online access to it is set as public so you can download it instantly. Our digital library spans in multiple countries, allowing you to get the most less latency time to download any of our books like this one. Kindly say, the design of analog cmos integrated circuits is universally compatible with any devices to read.

1,038 citations

Journal ArticleDOI
TL;DR: This review provides a summary of the widely reported electrical switching phenomena in polymers and the corresponding polymer electronic memories.

902 citations

Journal ArticleDOI
TL;DR: A comparison study of high-k Dielectric Materials for OFETs using self-Assembled Monoand Multilayers and Inorganic-Organic Bilayers to study the properties of polymeric-Nanoparticle Composites.
Abstract: 2.2. Interface Trapping Effects 211 3. High-k Dielectric Materials for OFETs 212 3.1. Inorganic Dielectrics 212 3.1.1. Aluminum Oxide 213 3.1.2. Tantalum Oxide 215 3.1.3. Titanium Dioxide 216 3.1.4. Hafnium Dioxide 217 3.1.5. Zirconium Dioxide 218 3.1.6. Cerium Dioxide 218 3.2. Organic Dielectrics 218 3.2.1. Polymer Dielectrics 218 3.2.2. Self-Assembled Monoand Multilayers 225 3.3. Hybrid Dielectrics 227 3.3.1. Polymeric-Nanoparticle Composites 227 3.3.2. Inorganic-Organic Bilayers 232 3.3.3. Hybrid Solid Polymer Electrolytes 235 4. Summary 235 5. Acknowledgments 236 6. References 236

788 citations

Journal ArticleDOI
TL;DR: In this article, a review of the state-of-the-art organic field effect transistors is presented, focusing on the problem of parameter extraction, limitations of the performance by the interfaces, which include the dielectric-semiconductor interface, and the injection and retrieval of charge carriers at the source and drain electrodes.
Abstract: With the advent of devices based on single crystals, the performance of organic field-effect transistors has experienced a significant leap, with mobility now in excess of 10 cm2 V−1 s−1. The purpose of this review is to give an overview of the state-of-the-art of these high-performance organic transistors. The paper focuses on the problem of parameter extraction, limitations of the performance by the interfaces, which include the dielectric–semiconductor interface, and the injection and retrieval of charge carriers at the source and drain electrodes. High-performance devices also constitute tools of choice for investigating charge transport phenomena in organic materials. It is shown how the combination of field-effect measurements with other electrical characterizations helps in elucidating this still unresolved issue.

649 citations