Title Promoter Affiliations Abstract "Physicochemical properties and chemical reactivity of 0D, 2D and 3D materials on the nanometer and micrometer scale." "Steven De Feyter" "Membrane Separations, Adsorption, Catalysis, and Spectroscopy for Sustainable Solutions (cMACS), Molecular Imaging and Photonics" "In spite of their resolving power, advanced light microscopy and spectroscopy techniques with very high spatial and/or temporal resolution, yield often little unambiguous information on the chemical structure of 2- and 3-dimensional nanostructures. Such information can be obtained by Raman based techniques where recent developments as tip-enhanced Raman spectroscopy or stimulated Raman scattering have sufficient spatial resolution and/or sensitivity to chemically identify single nano-objects or monolayers. The applicants will set-up and further develop those techniques and apply them to relate spatial, structural and functional information at the level of single nano-objects and in several complex and heterogeneous systems at the nanoscale, with a focus on surfaces and interfaces." "Dynamics and structural analysis of 2D materials (DYNASTY)." "Johan Verbeeck" "Condensed Matter Theory, Foundation for Research and Technology Hellas, Institut National des Sciences Appliquées (INSA Toulouse), Electron microscopy for materials research (EMAT)" "DYNASTY's primary objective is to build in the European South East, and in particular in the Foundation for Research and Technology Hellas (FORTH) in Crete, a significant pole of attraction for nanomaterials researchers and scientists. This will be accomplished through joint research activities and partnering with two well-established European research teams, which are in the forefront of nanomaterials research. The activities will contribute in scientific production that will motivate and attract young scientists in nanomaterials (e.g. 2D materials) science and technology. The partners include: (a) the University of Antwerp (UA) with strong expertise in advanced Electron Microscopy for Materials Science and in Condensed Matter Theory (the EMAT and CMT groups, respectively), which are both part of the UA NANOlab Center of Excellence (Belgium) (b) and the National Institute of Applied Sciences (INSA- University of Toulouse), with deep expertise in advanced spectroscopic characterization techniques of 2D materials. The activities involve training through cross-lab visits, workshops, short courses, joint conferences, and well-designed communication activities to attract young scientists at FORTH. All teams will provide their expertise and collaborate to build advanced Imaging and Spectroscopy expertise at FORTH (combining non-linear and time-resolved optical spectroscopies) that will provide precise fine structural analysis of 2D materials and their heterostructures. By the end of the three-year project, FORTH will gain advanced skills in nanomaterials characterization and knowhow in nanoelectronic devices fabrication. As a result, DYNASTY will create a collaborative platform for widening experimental networks among nanomaterials labs in Europe, enabling local teams to produce excellent interdisciplinary nanoscience, currently lacking in Greece." "Electron correlations and non-trivial band topology in 2D materials" "Michel Houssa" "Semiconductor Physics, Quantum Solid State Physics (QSP), Structural Composites and Alloys, Integrity and Nondestructive Testing (SCALINT)" "Phenomena originating from electron correlations and non-trivial band topology have become one of the main research areas in modern condensed matter physics. Many classes of materials have emerged including ferromagnets, superconductors, topological insulators, Mott insulators, Dirac/Weyl semimetals and quantum anomalous Hall insulators (QAHI). Moreover, when such materials are combined, new phenomena and functionalities emerge, such as Majorana states, which promise to enable topological quantum computation. While major research efforts have been dedicated to studying such phenomena in conventional 3D materials, the tremendous potential of 2D materials remains largely unexplored. Since these phenomena emerge from interface-mediated coupling in low-dimensionality (e.g. interfacing a QAHI and a superconductor), 2D materials and related layered systems are an ideal platform. In this project, we propose to: (i) develop and study 2D systems exhibiting electron correlation phenomena and non-trivial band topology; (ii) interfacing such materials and studying the emerging phenomena of relevance (e.g. Majorana states); (iii) drive these systems through different quantum states in device architectures. We will focus particularly on 2D oxides and chalcogenides and, taking advantage of the specific expertise in our consortium, apply beyond state-of-the-art techniques (theoretical and experimental) for in-situ growth and characterization down to the atomic scale as well as nanoscale device fabrication." "Chirality by design in magnetic 2D materials" "Milorad Milosevic" "Condensed Matter Theory" "Further technological advance of our modern society will critically depend on novel, all-in-one materials, able to couple magnetic, elastic, and electronic degrees of freedom in a controllable fashion. Atomically-thin 2D materials may be just what is needed, exhibiting a range of advanced properties, tunable by stretching, bending, gating, and/or heterostructuring. With advent of magnetism in 2D materials (only since 2017), tailoring their multifunctional behavior is at its prime potential. Magnetism in 2D materials is quite special, since any incurred symmetry change (with e.g. bending) affects magnetic interactions and causes adjacent magnetic moments to misalign, owing to strong emergent chirality, comparable to usual aligning interactions. Chiral interactions lead to observable nontrivial magnetic textures, such as skyrmions, and cause entirely different behavior of dynamic excitations (magnons), both of which bear documented technological promise. Symmetry breaking that causes chirality is also accompanied by local electric field, so that chiral magnetism and electric polarization in a 2D material are effectively coupled. This project is devoted to understanding of that coupling, and its response to standard manipulations within the realm of 2D materials, that will enable tailoring of chiral magneto-electronics practically at will, for actively and broadly tunable technology very sensitive to electric, magnetic, optical or mechanical stimuli." "Ab initio simulations of novel 2D materials and interfaces for advanced ICT applications" "Michel Houssa" "Semiconductor Physics, Surface and Interface Engineered Materials (SIEM)" "To continue the development and miniaturization of transistors, new materials and device concepts are required to be developed. This thesis provides a study of two new classes of materials, superlattices and two-dimensional (2D) materials, to assess their potential as a replacement for silicon in the transistor channel. To perform this analysis, modern modeling techniques are used to provide an atomistic description (molecular dynamics, first-principles simulations and quantum transport calculations) of these systems. New device concepts to replace the Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs) are also investigated, exploiting the benefits of these materials.The scaling of the physical dimensions of the transistors is reaching a state where a degradation of the performances and an increase in power consumption are encountered due to effects related to quantum mechanics. Silicon, the current building block of transistors, is approaching its limits in terms of scaling capabilities. As the channel length approaches 10 nm and its body becomes very thin, source-to-drain tunneling currents prevent the device from beingproperly turned off, while a quantum quantization effects occur and result in degraded carrier mobilities. In addition to this phenomenon, the thinning of the gate oxide leads to an increased gate leakage current. Therefore, to keep on shrinking the transistors and to reduce their power consumption, new materials with high carrier mobilities have emerged as potential replacements for silicon. This work concentrates on the one hand, on the investigation of superlattices, quasi-two-dimensional materials made of an alternation of a semiconductor layer (silicon or germanium) and of an interspersing species (oxygen, nitrogen or carbon). This approach is a promising alternative that allows tailoring the electronic properties of the transistor channel material. On the other hand, I focus on the fundamental properties of two-dimensional materials. Recently, this class of materials has emerged as potential a contender for future transistor designs, thanks to their self-passivated atomic configuration, high carrier mobilities and excellent electrostatic control that atomically thin materials offer. The physics of these materials is not yet well understood, especially in terms of the electronic properties and how the interactions with their surroundings impact on them.In parallel to the search for new materials, I also studied the applicability  of 2D materials to allow the development of an alternative device concept, the Tunnel Field-Effect Transistor (TFET). This device offers the potential to overcome the intrinsic limits of the MOSFET, whose power consumption can no longer be sufficiently reduced. The TFET is a low-power device that relies on a filtering of the energy distribution of the injected carriers, leading to a very steep switching from the OFF- to the ON-state. As a consequence, the supply voltage can be lowered, which contributes to the reduction of the heat dissipation.The main objective of this thesis consists in providing a fundamental understanding of the properties of superlattices and 2D materials to evaluate their potential as channel materials for field-effect transistors (both MOSFETs and TFETs). It aims at formulating guidelines for the design and the selection of materials for future electronic devices. Modern modeling techniques are used to evaluate at an atomistic level their structural, electronic and transport properties.  The results show that by selecting a proper atomic configuration, superlattices can improve the transport properties in the direction of the drive current (lower effective masses), while degrading them in the perpendicular direction. 2D materials are also shown to be promising alternatives for  MOSFETs, provided that a cautious choice of the material is performed. The thickness (or number of 2D layers) has to be carefully controlled to avoid a dielectric screening of the gate bias. Stacked into heterostructures, they also open the door towards the development of an alternative method of doping based on electrostatics, that allows to achieve high doping concentrations (more than 1e13 e/cm2). Incorporated in TFET channels, they enable the development of for low-power applications. However, the weak interaction forces acting between the layers lead to a variability of the performances in the device behavior." "Developing novel methodologies for the nano-optical characterization of 2D materials" "Hiroshi Ujii" "Molecular Imaging and Photonics, J.Heyrovsky Institute of Physical Chemis, Hokkaido University" "Traditional optical spectroscopies are unparalleled analytical tools in science. However, a fundamental physical barrier known as the diffraction limit prevents them from accessing length scales beneath 200 nanometres. This is especially problematic for the family of 2D materials, such as graphene and the transition metal dichalcogenides (TMDs), which hold promise for cheap, next-generation LEDs, photovoltaic cells and photodetectors, amongst many other applications. For 2D materials, properties are dictated at the nanoscale, making it critical to have optical tools beyond the diffraction limit. Tip-Enhanced Near-Field Optical Microscopy (TENOM) can provide the necessary resolution to analyse 2D materials, amongst a great many other systems. However, TENOM is notoriously difficult and hence is only practiced by a select number of research groups worldwide. The aim of this project is to develop new, highly reproducible methods for TENOM using metal nanowires and, thereafter, use TENOM to analyse standard and functionalised 2D materials. This will help to understand how order and disorder at the nanoscale can dictate properties at the macroscale. This knowledge shall then be validated through the production of primitive devices for applications. To summarise, this project hopes to overcome the problems of TENOM and then, using 2D materials as an example, show it has a unique ability to bring the analytical power of light to the nanometre scale. " "Plasma Physics and Chemistry Challenges for the Interconnect Technology of 2D Materials." "Stefan De Gendt" "Sustainable Chemistry for Metals and Molecules" "Transition-metal dichalcogenides such as MoS2 or WS2 are semiconducting materials with a layered structure. One single layer consists of a plane of metal atoms terminated on the top and bottom by the chalcogen atoms sulfur, selenium, or tellurium. These layers show strong in-plane covalent bonding, whereas the Van-der-Waals bonds in between adjacent layers are weak. Those weak bonds allow the microcleavage and extraction of a monolayer. Transistors built on such monolayer nanosheets are promising due to high electrostatic controllability in comparison to a bulk semiconductor. This is important for fast switching speed and low-power consumption in the OFF-state. Nonetheless, prototypes of such nanosheet transistors show non-idealities due to the fabrication process. Closed films on a large area cannot be obtained by mechanical exfoliation from mm-sized crystals. For  wafer-level processing, synthetic growth methods are needed. It is a challenge to obtain a few layer thick crystals with large lateral grains or even without grain boundaries with synthetic growth techniques. This requires pre-conditioned monocrystalline substrates, high-temperature deposition, and polymer-assisted transfer to other target substrates after the growth. Such transfer is a source of cracks in the film and degrades the layers’ promising properties by residual polymer from the bond material. Apart from transfer, patterning of the stacked 2D layers is necessary to build devices. The patterning of a 2D material itself or another material on top of it is challenging. The integration of the nanosheets into miniaturized devices cannot be done by conventional continuous-wave dry etching techniques due to the absence of etch stop layers and the vulnerability of these thin layers. To eliminate these issues in growth and integration, we explored the deposition methods on wafer-level and low-damage integration schemes.To this end, we studied the growth of MoS2 by a hybrid physical-chemical vapor deposition for which metal layers were deposited and subsequently sulfurized in H2S to obtain large area 2D layers. The impact of sulfurization temperature, time, partial H2S pressure, and H2 addition on the stoichiometry, crystallinity, and roughness were explored. Furthermore, a selective low-temperature deposition and conversion process at 450 °C for WS2 by the precursors WF6, H2S, and Si was considered. Si was used as a reducing agent for WF6 to deposit thin W films and H2S sulfurized this film in situ. The impact of the reducing agent amount, its surface condition, the temperature window, and the necessary time for the conversion of Si into W and W into WS2 were studied. Further quality improvement strategies on the WS2 were implemented by using extra capping layers in combination with annealing. Capping layers such as Ni and Co for metal-induced crystallization were compared to dielectric capping layers. The impact of the metal capping layer and its thickness on the recrystallization was evaluated. The dielectric capping layer’s property to suppress sulfur loss under high temperature was explored. The annealings, which were done by rapid thermal annealing and nanosecond laser annealing, were discussed.Eventually, the fabrication of a heterostack with a MoS2 base layer and selectively grown WS2 was studied. Atomic layer etching was identified as attractive technique to remove the solid precursor Si from MoS2 in a layer-by-layer fashion. The in-situ removal of native SiO2 and the impact towards MoS2 was determined. The created patterned Si on MoS2 was then converted into patterned WS2 on MoS2 by the selective WF6/H2S process developed earlier. This procedure offers an attractive, scalable way to enable the fabrication of 2D devices with CMOS-compatible processes and contributes essential progress in the field 2D materials technology." "Topological and electron correlation phenomena in 2D / layered materials." "Lino da Costa Pereira" "Quantum Solid State Physics (QSP)" "Studying phenomena arising from electron correlations and nontrivial band topology has become one of the most important areas of research in modern solid-state physics. This results in a variety of (new) material types: ferromagnets, superconductors, topological insulators, Mott insulators, Dirac/Weyl semi-metals and anomalous quantum Hall insulators (QAHI). Moreover, when such materials are combined, unique phenomena and functionalities arise at their interfaces, including Majorana particles. In the future, these particles may allow us to perform so-called topological quantum calculations. Although major research efforts have been made to study such phenomena in conventional 3D materials, the vast potential of 2D materials remains largely unexplored. Since these phenomena arise from surface-mediated coupling (eg bringing together the surfaces of a QAHI and a superconductor), 2D materials and related layered systems are an ideal platform. In this project we will: (i) develop and study 2D systems that exhibit phenomena of electron correlations and nontrivial band topology; (ii) couple such materials together in hybrid structures and study their electronic properties; (iii) manipulate the observed quantum states of these systems in electronic nanocircuits. We will focus in particular on 2D oxides and chalcogenides. For this, we use the specific expertise available in our consortium and the available state-of-the-art techniques (both theoretical and experimental) regarding in-situ growth and characterization at the atomic scale and the creation of electronic nano-circuits for potential applications." "Redesigning 2D Materials for the Formulation of Semiconducting Inks" "Steven De Feyter" "Molecular Imaging and Photonics" "2D-INK is targeted at developing inks of novel 2D semiconducting materials for low-cost large-area fabrication processes on insulating substrates through a new methodology, which will exceed the properties of state-of-the-art graphene- and graphene oxide based inks. Achieving this would represent an important step forward in the processing of 2D semiconducting materials and will provide the key parameters for fabricating the next generation of ultrathin electronic appliances.The inherent high-risk of 2D-INK is countered by a strongly interdisciplinary research team composed of 9 partners (8 academics + 1 SME) with demonstrated experience in their corresponding fields and with different yet highly complementary backgrounds. Therefore only together and in synergy they will be able to address the challenges of the multiple research and innovation aspects of 2D-INK that cover the entire value chain from materials design and synthesis, characterisation, formulation and processing to device implementation.In addition 2D-INK has the potential to revolutionise research on 2D semiconducting materials way beyond the current interests on synthesis (high impact), since the efficient dispersion and formulation of 2D semiconducting materials into inks enables the applications of 2D semiconducting materials over different scientific and technological disciplines, such as electronics, sensing, photonics, energy storage and conversion, spintronics, etc.Overall, 2D-INK addresses perfectly the challenge of this call as it is an archetype of an early stage, high risk visionary science and technology collaborative research project that explores radically new manufacturing and processing technologies for novel 2D semiconducting materials." "Heterojunction Tunnel FETS using 2D Materials as Channel" "Guido Groeseneken" "ESAT - MICAS, Microelectronics and Sensors" "2D materials research has been shifting towards novel electronic and optical applications apart from conventional MOSFETs. Their atomically flat surfaces and self-passivated layers offer potentially defect free inter-layer tunneling. Band-to-band tunneling field effect transistors (TFET) have caught the attention of industry and academia for over a decade in CMOS scaling with the promise of obtaining a steep Subthreshold Swing, SS < 60mV/dec at room temperature Achieving a low supply voltage and obtaining a high enough on current and steep SS are crucial in 2D TFETs for future CMOS technologies. However when compared to simulations, experiments are still far fetchedfrom reaching the required performance. Hence, the goal of this thesis is to systematically identify and characterize the parasitics limiting high ION and steep SS in 2D TFETs. We achieve this by fabricating 2D heterojunction TFETs based on MoS2-MoTe2 and ReS2-BP. The parasitics that we focus on are 1) Schottky barriers at the contacts, 2) impact of different current components on TFET performance 3) impact of multiple layers on BTBT and gate electrostatics, 4) device gate configuration on BTBT transport, 5) impact of indirect and direct BTBT on ION and SS, 6) point tunneling and 7) Material anisotropy on carrier transport.In the first part on MoS2-MoTe2 TFETs, we perform our experiments using three different gate configurations. These allow us to address the transport mechanisms characteristic of each configuration. Due to our inability to dope the contact regions, we observe significant degradation of BTBT current. In order to isolate the contacts’ influence, we then introduce a contact gated architecture that decouples the influence of the contacts from the channel. We also assess the long tunneling paths arising from tunneling across multiple 2D layers using Quantum transport simulations. These findings provide additional insights on investigating the impact of gate configuration and indirect tunneling on the device performance.In the second part, BP-ReS2 TFETs are fabricated with different flake thicknesses to identify the most favorable configuration for TFETs. Further optimizations are demonstrated to reduce the equivalent oxide thickness (EOT) of the gate dielectric to obtain a lower SS and to reduce the gate leakage. From the electrical measurements, we demonstrate that tunneling happens only at the edge of the heterojunction, which is also known as point tunneling. Finally, we study the anisotropic transport in BP-ReS2 TFETs by investigating the anisotropy in BP on the BTBT current and the SS of the TFET. Combining all the outcomes of this work, the thesis thus provides the necessary framework to implement 2D TFETs for beyond CMOS technology. "