Gate-controlled reversible rectifying behaviour in tunnel contacted atomically-thin MoS2_{2} transistor

Atomically-thin 2D semiconducting materials integrated into van der Waals heterostructures have enabled architectures that hold great promise for next generation nanoelectronics. However, challenges still remain to enable their full acceptance as compliant materials for integration in logic devices. Two key-components to master are the barriers at metal/semiconductor interfaces and the mobility of the semiconducting channel, which endow the building-blocks of ${pn}$ diode and field effect transistor. Here, we have devised a reverted stacking technique to intercalate a wrinkle-free h-BN tunnel layer between MoS$_{2}$ channel and contacting electrodes. Vertical tunnelling of electrons therefore makes it possible to suppress the Schottky barriers and Fermi level pinning, leading to homogeneous gate-control of the channel chemical potential across the bandgap edges. The observed unprecedented features of ambipolar ${pn}$ to ${np}$ diode, which can be reversibly gate tuned, paves the way for future logic applications and high performance switches based on atomically thin semiconducting channel.Comment: 23 pages, 5 main figures + 9 SI figure

Reconfigurable Complementary Logic Circuits with Ambipolar Organic Transistors

Ambipolar organic electronics offer great potential for simple and low-cost fabrication of complementary logic circuits on large-area and mechanically flexible substrates. Ambipolar transistors are ideal candidates for the simple and low-cost development of complementary logic circuits since they can operate as n-type and p-type transistors. Nevertheless, the experimental demonstration of ambipolar organic complementary circuits is limited to inverters. The control of the transistor polarity is crucial for proper circuit operation. Novel gating techniques enable to control the transistor polarity but result in dramatically reduced performances. Here we show high-performance non-planar ambipolar organic transistors with electrical control of the polarity and orders of magnitude higher performances with respect to state-of-art split-gate ambipolar transistors. Electrically reconfigurable complementary logic gates based on ambipolar organic transistors are experimentally demonstrated, thus opening up new opportunities for ambipolar organic complementary electronics.115Ysciescopu

Balancing Hole and Electron Conduction in Ambipolar Split-Gate Thin-Film Transistors

Complementary organic electronics is a key enabling technology for the development of new applications including smart ubiquitous sensors, wearable electronics, and healthcare devices. High-performance, high-functionality and reliable complementary circuits require n- and p-type thin-film transistors with balanced characteristics. Recent advancements in ambipolar organic transistors in terms of semiconductor and device engineering demonstrate the great potential of this route but, unfortunately, the actual development of ambipolar organic complementary electronics is currently hampered by the uneven electron (n-type) and hole (p-type) conduction in ambipolar organic transistors. Here we show ambipolar organic thin-film transistors with balanced n-type and p-type operation. By manipulating air exposure and vacuum annealing conditions, we show that well-balanced electron and hole transport properties can be easily obtained. The method is used to control hole and electron conductions in split-gate transistors based on a solution-processed donor-acceptor semiconducting polymer. Complementary logic inverters with balanced charging and discharging characteristics are demonstrated. These findings may open up new opportunities for the rational design of complementary electronics based on ambipolar organic transistors. ? 2017 The Author(s).114Ysciescopu

Integrated Circuit Design for High Data Rate Polymer Microwave Fiber Communication

The rapid development of semiconductor processes with a maximum frequency of oscillation well above 300 GHz enables new applications at frequencies above 100 GHz to be researched and developed. Such applications include wireless backhaul, wireless access, radar and radiometer sensors, wireless energy distribution and harvesting, etc.\ua0For several of these applications, a throughput in data rate well above 10 Gbps, even up to 100 Gbps, is required. Optical fiber communication is the leading option for high data rate and long-range wired communication. However, for shorter ranges like chip-to-chip or module-to-module (up to ten meters), millimeter-wave communication over a polymer microwave fiber (PMF) is an interesting alternative due to its potential low cost. Other advantages include flexibility, less sensitivity to temperature variations, and a more relaxed mechanical tolerance requirement. Similar to optical fiber, dispersion occurs on PMFs and will cause symbol interference. Different ways to deal with this effect are investigated, for example, pulse shaping and equalization of the signal.\ua0This work proposes and presents various circuit solutions enabling high data rate communication. Two technologies are used, 250 nm InP DHBT and 130 nm SiGe BiCMOS. An energy-efficient solution using an RF-DAC and power detector for pulse amplitude modulated links are evaluated, as well as an I/Q modulated solution. I/Q (de-)modulators require more complexity, but the increased spectral efficiency can also increase the data rate further.\ua0\ua0In summary, I explore the opportunities and challenges of short-range, ultra-high data rate, PMF bound communication, which is found to support 56 Gbps error-free (BER<10-12) data and 102 Gbps with a BER=2.1*10-3

Integrated Circuit Solutions for High Datarate Polymer Fiber Communication

Most societies today are dependent on an Internet connection. It has to be reliable in any condition, energy efficient, but most importantly fast. High data rate communication is urgently needed, not only to connect one part of the world to the other, but also for short range applications to help us get through the day. Communication within an autonomous car, to get us from point A to point B, streaming entertainment at a Friday night, or parts of a production chain to help out at a factory. The transmitters and receivers are key components to transfer the data to make these kind of applications possible. Adjustments to what is available and possible is what challenges the progress. Fundamental limitations comes from the material properties and available energy in comparison to the noise around us. Dealing with bandwidth limitations is somewhat man-made, but the interference of different signals is completely real. Looking around for opportunities in this world leads you to look for free bandwidths. The millimeterwave-band (30-300 GHz) offers available bandwidth as well as other benefits. In this work, different circuit solutions enabling high data rate communication is proposed and presented. Different technologies are used, like state of the art processes and commercial processes. Wirebound communication through polymer microwave fiber (PMF) using energy efficient RF-DAC based modulators and power detectors (PDs) is a cheap and robust solution. In this work we explore the opportunities of short range, ultra high data rate, PMF bound communication, which is found to support 30 Gbps error free (BER<10^-12) data

A unipolar inverter drive for a cage induction motor

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