Masiar Sistani

TU Wien | TU Wien · Institute of Solid State Electronics

2D materials provide a rapidly expanding platform for the observation of novel physical phenomena and for the realization of cutting-edge optoelectronic devices. In addition to their peculiar individual characteristics, 2D materials can be stacked into complex van der Waals heterostructures, greatly expanding their potential. Moreover, thanks to th...

Reproducible and deterministically defined metal-semiconductor heterojunctions are of utmost importance for next-generation nanoelectronics. Here, we integrate bottom-up synthesized Si and Ge nanowires (NW) in Schottky barrier field effect transistors (SBFET). Key for the fabrication of these devices is the controllable solid-state exchange of Si a...

Modern computing is demanding ever more complex integrated circuits. Two emerging concepts that integrate a higher expressiveness per elementary unit, thereby reducing overall transistor count and power consumption vs. conventional technology, are reconfigurable field effect transistors (RFETs) and multi-valued logic (MVL) devices. RFETs are capabl...

Liquid spectroscopy in the mid-infrared spectral range is a very powerful, yet premature technique for selective and sensitive molecule detection. Due to the lack of suitable concepts and materials for versatile miniaturized sensors, it is often still limited to bulky systems and offline analytics. Mid-infrared plasmonics is a promising field of cu...

In this paper, we exploit the nanometer scale properties of Ge based Schottky barrier field-effect transistors (SBFETs) with monocrystalline Al contacts, fusing the concept of reconfiguration and negative differential resistance (NDR) in a single device. Temperature dependent bias spectroscopy is used to investigate the electronic transport in the...

Overcoming the difficulty in reproducibility and deterministically defining the metal phase of metal-semiconductor heterojunctions is among the key prerequisites to enable next-generation nanoelectronic, optoelectronic and quantum devices. In this respect, a comprehensive understanding of the charge carrier injection and the electronic conduction m...

We present recent progress in monolithic mid-infrared photonic integrated circuits (PICs) for sensitive and selective real-time analysis of liquids. Our lab-on-a-chip spectrometers are based on quantum cascade (QC) technology using advanced plasmonic sensing schemes. We further demonstrate surface-passivation/-functionalization and on-chip beam gui...

In this work, monolithic, and crystalline Al–Ge–Al heterostructure nanowire field effect transistors (FETs) with Ge channel lengths ranging from 18 to 826 nm are analyzed from a low-frequency noise perspective. 1/f and random telegraph noise (RTN) are analyzed in an accumulation mode, where the hole channel is formed by applying a back-gate potenti...

Overcoming the difficulty in reproducibility and deterministically defining the metal phase of metal-semiconductor heterojunctions is among the key prerequisites to enable next-generation nanoelectronic, optoelectronic and quantum devices. In this respect, a comprehensive understanding of the charge carrier injection and the electronic conduction m...

In this work, bottom-up and top-down structured Al-Si-Al heterostructure devices are integrated in a three top-gate architecture enabling reconfigurable transistors. Therefore, VLS grown Si nanowires (NWs) and nanosheets structured from silicon-on-insulator substrates are used as starting material. Utilizing TEM and EDX, the Al-Si interface was ana...

Si1-xGex is a key material in modern complementary metal-oxide-semiconductor and bipolar devices. Importantly SiGe and Ge are promising materials to enable higher drive currents, reduced power consumption and enhanced switching speeds. However, despite considerable efforts in metal-silicide and-germanide compound material systems, reliability conce...

Liquid spectroscopy in the mid-infrared spectral range is a very powerful, yet premature technique for selective and sensitive molecule detection. Due to the lack of suitable concepts and materials for versatile miniaturized sensors, it is often still limited to bulky systems and offline analytics. Mid-infrared plasmonics is a promising field of cu...

The generation of hot carriers by Landau damping or chemical interface damping of plasmons is of particular interest to the fundamental aspects of extreme light-matter interactions. Hot charge carriers can be transferred to an attached acceptor for photochemical or photovoltaic energy conversion. However, these lose their excess energy and relax to...

Reconfigurable field-effect transistors, capable of being dynamically programmed during run-time, overcome the static nature of conventional complementary metal-oxide semiconductors by reducing the transistor count and the circuit path delay. Thereby, SiGe and Ge are predicted to boost drive currents, switching speed and to reduce power consumption...

With the emerging transition from programmed to learning computing, traditional electronic ICs are unlikely to be able to match the massive perceptual data that will need to be processed in real-time. Neuromorphic engineering may surmount the von Neumann bottleneck by creating high-performance hardware for distributed and parallel processing with l...

Si_1-xGe_x nanowires (NWs) were prepared by gold-supported chemical vapor deposition (CVD) using a single-source precursor with preformed Si-Ge bonds. Besides the tamed reactivity of the precursor, the approach reduces the process parameters associated with the control of decomposition characteristics and the dosing of individual precursors. The gr...

We present recent progress in monolithic mid-infrared photonic integrated circuits (PICs) for sensitive and selective real-time analysis of liquids. Our lab-on-a-chip spectrometers are based on quantum cascade (QC) technology using advanced plasmonic sensing schemes. We further demonstrate surface-passivation/-functionalization and on-chip beam gui...

Surface plasmon polaritons (SPPs) combine the high-speed capabilities of photonic circuits with the ability of plasmonic confinement below the diffraction limit. In particular, modes supported at (noble) metal/dielectric interfaces in various configurations have gained great attention owing to their prospects for attractive applications. However, c...

A series of new mixed-substituted heteronuclear precursors with preformed Si−Ge bonds has been synthesized via a two-step synthesis protocol. The molecular sources combine convenient handling with sufficient thermal lability to provide access to group IV alloys with low carbon content. Differences in the molecule−material conversion by chemical vap...

High-quality electrical contacts are of utmost importance for nanoscale devices as they have a large impact on their electrical performance, reliability and reproducibility. Furthermore, as the CMOS scaling is about to approach fundamental physical limits, new device concepts are needed to further increase the functionality of electronic systems....

Typically used visible and near-IR plasmon-based sensors in analytical chemistry and bio-sensing show limited sensitivity, together with complex miniaturization for integrated lab-on-a-chip devices. In order to improve both aspects, it is beneficial to use coherent mid-IR laser light, exploiting the stronger absorptions of molecules of interest in...

SiGe is a key material in modern complementary metal-oxide-semiconductor and bipolar devices. However, despite considerable efforts in metal-silicide and -germanide compound material systems, reliability concerns have so far hindered the implementation of metal-SiGe junctions that are vital for diverse emerging “More than Moore” and quantum computi...

Direct-write techniques for the fabrication of nanostructures are of specific interest due to their ability for a maskless fabrication of any arbitrary three-dimensional shape. To date, there is a very limited number of reports describing differences in the focused ion and electron beam induced deposition (FIBID/FEBID) for the same precursor specie...

High-quality electrical contacts are of utmost importance for nanoscale Si devices as they have a large impact on their electrical performance, reliability and reproducibility. Furthermore, as the CMOS scaling is about to approach fundamental physical limits, new device concepts are needed to further increase the functionality of electronic systems...

The functional diversification and adaptability of the elementary switching units of computational circuits are disruptive approaches for advancing electronics beyond the static capabilities of conventional CMOS. In this respect, two emerging concepts in electronics are dopingfree reconfigurable FETs (RFETs) capable of dynamically altering the devi...

Overcoming the difficulty in reproducibility and deterministically defining the metal phase of metal-Si heterostructures is among the key prerequisites to enable next-generation nanoelectronic devices. Here, the formation of monolithic Al-Si-Al heterostructures obtained from Si nanowires and Al contacts is presented. Transmission electron microscop...

Supporting Information of the paper "Reconfigurable Complementary and Combinational Logic Based on Monolithic and Single‐Crystalline Al‐Si Heterostructures".

Metal-semiconductor heterostructures providing geometrically reproducible and abrupt Schottky nanojunctions are highly anticipated for the realization of emerging electronic technologies. This specifically holds for reconfigurable field-effect transistors, capable of dynamically altering the operation mode between n- or p-type even during run-time....

Mid-infrared (mid-IR) spectroscopy is a powerful tool for probing the fingerprint absorptions of molecules in gas and liquid phase, particularly important for the chemical and biomedical fields. Thanks to the development of high-performance quantum cascade lasers (QCLs) and detectors (QCDs), new analytical methods can be developed to enable a new c...

Metal-semiconductor nanojunctions providing geometrically reproducible and abrupt Schottky junctions are highly anticipated for the realization of several emerging electronic technologies. This specifically holds for reconfigurable field-effect transistors (RFET) that are capable of dynamically altering the operation mode between n- or p-type even...

Supporting Information of our paper "Monolithic and Single-Crystalline Aluminum-Silicon Heterostructures".

Overcoming the difficulty in the precise definition of the metal phase of metal−Si heterostructures is among the key prerequisites to enable reproducible next-generation nanoelectronic, optoelectronic, and quantum devices. Here, we report on the formation of monolithic Al−Si heterostructures obtained from both bottom-up and top-down fabricated Si n...

With classical scaling of CMOS transistors according to Dennard’s scaling rules running out of steam, new possibilities to increase the functionality of an integrated circuit at a given footprint are becoming more and more desirable. Among these approaches the possibility to reconfigure the functionality of a transistor on the single devices level...

Group-IV based nanodevices are an active area of research for CMOS-compatible photonic components in the visible and near-infrared region, covering the C-band optical communication range. Especially, nanowires (NWs) have gained significant interest, due to their inherent nanocylinder resonator shape, allowing light trapping in circulating orbits by...

Group IV elements are essential for modern standards of life including Si-based science and technology in a multitude of applications. Even though semiconductor technology based on group IV is a very mature field, the physical properties can be altered by the formation of metastable solid solutions possessing significantly altered physical properti...

The functional diversification and adaptability of the elementary switching units of computational circuits are disruptive approaches for advancing electronics beyond the static capabilities of conventional CMOS. In this respect, two emerging concepts in electronics are doping-free reconfigurable FETs (RFETs) capable of dynamically altering the dev...

Nanoscale Ge devices are attractive for both fundamental studies of low-dimensional nanostructures as well as for future high-performance nanoelectronic and quantum devices. Along with confinement effects, the inherently high surface-to-volume ratio of nanostructures causes their properties to strongly depend on the surface. Due to the presence of...

High-quality electrical contacts are of utmost importance for nanoscale devices as they have a large impact on their electrical performance, reliability and reproducibility. Nanowires (NWs) are of particular interest to ultra-scaled transistors because of their enhanced suppression of short channel effects. Especially, a deterministic top-down NW p...

Near-infrared detection is widely used for nondestructive and non-contact inspections in various areas, including thermography, environmental and chemical analysis as well as food and medical diagnoses. Common room temperature bolometer-type infrared sensors are based on architectures in the µm range, limiting miniaturization for future highly inte...

Semiconductor-loaded plasmonic (SLSPP)-waveguides are a very efficient link for optoelectronic devices, facilitating miniaturized photonic integrated circuits. However, for long-wave infrared applications (8-12 µm), the material selection is challenging as most commonly used mid-IR materials absorb in this region. Therefore, we selected and investi...

Recent advances in nanoscale optoelectronic Ge devices have exposed their enormous potential for highly sensitive visible and near-infrared CMOS compatible photodetectors. In this respect, Ge nanowires, due to their nanocylinder resonator shape, have established themselves as a promising platform to significantly enhance the performance of photodet...

Supporting Information of our paper "Bias-Switchable Photoconductance in a Nanoscale Ge Photodetector Operated in the Negative Differential Resistance Regime".

Plasmonic waveguides are crucial building blocks for integrated on-chip midinfrared (mid-IR) sensors, which have recently attracted great interest as a sensing platform to target enhanced molecular sensing. However, while hosting a wide range of applications from spectroscopy to telecommunication, the mid-IR lacks suitable broadband solutions that...

Supporting Information of our paper "Nanometer-Scale Ge-Based Adaptable Transistors Providing Programmable Negative Differential Resistance Enabling Multivalued Logic".

Supporting information of our paper "A Top-Down Platform Enabling Ge Based Reconfigurable Transistors".

Conventional field-effect transistor (FET) concepts are limited to static electrical functions and demand extraordinarily steep and reproducible doping concentration gradients. Reaching the physical limits of scaling, doping-free reconfigurable field-effect transistors (RFETs) capable of dynamically altering the device operation between p- or n-typ...

To establish high-bandwidth chip-to-chip interconnects in optoelectronic integrated circuits (OEICs), it requires high-performance photon emitters and signal receiving components. Regarding the photodetector fast device concepts like Schottky junction devices, large carrier mobility materials and shrinking the channel length will enable higher oper...

Since MOS scaling, metallic interconnect causes limitations of data rate and ultrahigh power dissipation. Compared with electrical interconnects, optical interconnects allow higher operation speed and lower power consumption for high-bandwidth-density chip-to-chip interconnects. However, for important components of optoelectronic integration circui...

Information and communication technology has become ubiquitous in everyday life. Emerging distributed computing paradigms such as the Internet of Things are demanding the implementation of novel electronic device functionalities that go beyond the capabilities of conventional field effect transistors. In this context, nanometer scale Ge departs fro...

Waveguides are a crucial building block for on-chip optics and mid-IR sensors. Plasmonic waveguides, in particular, can offer various advantages including sub-wavelength mode confinement and their suitability as highly sensitive molecular sensing platforms. In recent years there has been a surge of research aiming to identify new plasmonic media fo...

Ge-based Reconfigurable Transistors: A Platform Enabling Negative Differential Resistance

Modern transistor topologies are limited to static electrical functions and demand extraordinarily steep and reproducible doping concentration gradients at the junctions. Reaching the physical limits of scaling, doping-free reconfigurable field-effect transistors (RFETs), capable of integrating logic functions in a complementary design by dynamical...

Dielectric-Loaded Surface-Plasmon-Polariton waveguides (DLSPPWs) offer suitable solutions to guide mid-IR light along the surface of semiconductor-based optoelectronic devices. Since the main portion of the mode in typical semiconductor-Au-Ge plasmonic layer structures is propagating outside in the surrounding medium, this geometry allows to effici...

Many molecules of interest in chemistry and life science have their fingerprint absorptions in the mid-infrared (mid-IR), some of them extending to the Long-Wave Infrared (LWIR, 8-12 μm), including e.g. ammonia, glucose and TATP. Noteworthy, significant progress in the monolithic integration of fast and compact mid-IR sources, i.e. (QCLs) and detec...

Metal-semiconductor-metal heterostructures are an attractive platform for both fundamental studies of low-dimensional nanostructures as well as future high-performance low power dissipating nanoelectronic and quantum devices. Most notably, they provide enormous potential for a vast array of key components for quantum computing such as SQUIDs, oscil...

The longwave-infrared holds various applications ranging from sensing and imaging to optical free-space-communication. The increasing demand for miniaturized systems requires the development of compact photonic networks between on-chip optoelectronic components such as lasers, detectors and modulators. To resolve this challenging task, we introduce...

This is the supporting information of our paper "Al–Ge–Al Nanowire Heterostructure: From Single-Hole Quantum Dot to Josephson Effect".

Superconductor-semiconductor-superconductor heterostructures are attractive for both fundamental studies of quantum phenomena in low dimensional hybrid systems as well as for future high-performance low power dissipating nanoelectronic and quantum devices. Within this paper, ultra-scaled monolithic Al-Ge-Al nanowire heterostructures featuring monoc...

Supporting Information of our Paper: "Plasmon-Driven Hot Electron Transfer at Atomically Sharp Metal-Semiconductor Nanojunctions".

Supporting Information of our paper: "Nanoscale aluminum plasmonic waveguide with monolithically integrated germanium detector: Supporting Information".

Dielectric loaded plasmonic waveguides are a very efficient link for electronic and photonic devices, facilitating miniaturized on-chip optoelectronic integrated circuits. For longwave infrared applications (8-12 μm) however, the material selection is challenging as most common dielectrics like PMMA or Silica absorb in this wavelength range. In thi...

The ability to stack nanosheet transistors is an important prerequisite for the realization of vertically monolithic 3D integrated circuits enabling higher integration densities of functions and novel circuit topologies that relax miniaturization constrains. In this respect, we present a wafer-scale platform embedding high-quality nanoscale polycry...

Supporting Information regarding our publication "Polycrystalline Ge Nanosheets Embedded in Metal-Semiconductor Heterostructures Enabling Wafer-Scale 3D Integration of Ge Nanodevices with Self-Aligned Al Contacts".

Supporting information regarding our paper "Coulomb blockade in monolithic and monocrystalline Al-Ge-Al nanowire heterostructures".

The diverse applications and rich physics of hybrid superconducting-semiconducting systems has attracted significant research interest in improving the quality of these devices. Significant focus has been made on hybrid systems using a combination of Ge and Si to form a high mobility hole gas. However, there has been little research on pure Ge syst...

Supporting information regarding our publication "Stimulated Raman Scattering in Ge Nanowires"

Supporting information regarding our paper "Verifying the band gap narrowing in tensile strained Ge nanowires by electrical means".

Supporting information regarding our paper "Monolithic Metal-Semiconductor-Metal Heterostructures Enabling Next-Generation Germanium Nanodevices".

Low-dimensional Ge is perceived as a promising building block for emerging optoelectronic devices. Here, we present a wafer-scale platform technology enabling monolithic Al-Ge-Al nanostructures fabricated by a thermally induced Al-Ge exchange reaction. Transmission electron microscopy confirmed the purity and crystallinity of the formed Al segments...

Supporting information regarding our paper "Gate-Tunable Negative Differential Resistance in Next-Generation Ge Nanodevices and their Performance Metrics".