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a) Direct growth of 2D-materials-based vertical heterostructures by CVD with (i) h-BN by exploiting ammonia borane as precursor and ii) graphene onto the as-grown h-BN layers. b) Growth by either CVD or MBE of individual 2D materials and subsequent dry transfer using pick and place techniques enabling, in principle, any combination of different 2D materials. c) The relative orientation of the different layers of 2D materials is key and mandatory to be controlled to design i) vertically aligned and ii) controlled twist heterostructures. d) Lateral heterostructures can be realized i) by seeding an already grown 2D material template, ii) grow a second 2D material by using the appropriate precursors; and iii) by a proper placement of seeds through either a pattern and etch process or a mask, which can allow the realization of different lateral heterostructures such as linear, zigzag and donut-like shape. e) i) Direct growth of h-BN on graphene edges; ii) Scanning electron microscopy image showing a concentric h-BN/graphene heterostructure; iii) Optical image of a graphene/h-BN array of circles, with graphene circles embedded in an h-BN matrix. Panel i) in c) Courtesy of Profs. M. Kim and E. Tutuc, panel ii) and iii) in e) adapted from Ref. [15]. 

a) Direct growth of 2D-materials-based vertical heterostructures by CVD with (i) h-BN by exploiting ammonia borane as precursor and ii) graphene onto the as-grown h-BN layers. b) Growth by either CVD or MBE of individual 2D materials and subsequent dry transfer using pick and place techniques enabling, in principle, any combination of different 2D materials. c) The relative orientation of the different layers of 2D materials is key and mandatory to be controlled to design i) vertically aligned and ii) controlled twist heterostructures. d) Lateral heterostructures can be realized i) by seeding an already grown 2D material template, ii) grow a second 2D material by using the appropriate precursors; and iii) by a proper placement of seeds through either a pattern and etch process or a mask, which can allow the realization of different lateral heterostructures such as linear, zigzag and donut-like shape. e) i) Direct growth of h-BN on graphene edges; ii) Scanning electron microscopy image showing a concentric h-BN/graphene heterostructure; iii) Optical image of a graphene/h-BN array of circles, with graphene circles embedded in an h-BN matrix. Panel i) in c) Courtesy of Profs. M. Kim and E. Tutuc, panel ii) and iii) in e) adapted from Ref. [15]. 

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Quantum engineering entails atom-by-atom design and fabrication of electronic devices. This innovative technology that unifies materials science and device engineering has been fostered by the recent progress in the fabrication of vertical and lateral heterostructures of two-dimensional materials and by the assessment of the technology potential vi...

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... most important challenge, for devices based on both lateral and vertical heterostructures, is the preparation of the basic materials followed by their integration in the desired device structure. While vertical heterostructures, in principle, can be formed by direct growth (Fig. 1a) or by a transfer process for planar geometries (Fig. 1b), lateral heterostructures must be grown in place by some chemical means. At present, three methods are used or are under evaluation for the fabrication of 2D materials-based heterostructures 58 : (1) layer-by-layer stacking via mechanical transfer of CVDgrown films and exfoliated ...
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... most important challenge, for devices based on both lateral and vertical heterostructures, is the preparation of the basic materials followed by their integration in the desired device structure. While vertical heterostructures, in principle, can be formed by direct growth (Fig. 1a) or by a transfer process for planar geometries (Fig. 1b), lateral heterostructures must be grown in place by some chemical means. At present, three methods are used or are under evaluation for the fabrication of 2D materials-based heterostructures 58 : (1) layer-by-layer stacking via mechanical transfer of CVDgrown films and exfoliated natural or synthetic bulk-grown 2D materials; (2) direct ...
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... placement of 2D materials via mechanical transfer is the only technique that has been successfully used to create heterostructures and heterostructure devices. The method has relied principally on the mechanical exfoliation of bulk layered materials into atomically thin sheets 59 , but more recently the direct transfer of CVD-grown films (Fig. 1b) has also been used. The method has been extensively used for graphene, bilayer graphene, h-BN and TMDs to fabricate various stacked devices 60 . While transfer techniques of synthetic films or exfoliated layers from natural or synthetic bulk crystals have enabled the demonstration of many proof-of-principle stacked devices, allowing ...
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... and placement of the 2D films, many opportunities will emerge for the integration of these material structures in semiconductor manufacturing flows. The ideal or preferred case would be to use MBE, CVD and ALE processes to create/grow in situ new heterostructures. However, it is envisioned that the growth of on-demand aligned heterostructures (Fig. 1a) using these techniques could be extremely difficult, particularly in the case of twisted layers (Fig. ...
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... in semiconductor manufacturing flows. The ideal or preferred case would be to use MBE, CVD and ALE processes to create/grow in situ new heterostructures. However, it is envisioned that the growth of on-demand aligned heterostructures (Fig. 1a) using these techniques could be extremely difficult, particularly in the case of twisted layers (Fig. ...
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... h-BN in that wafer-scale single crystals are still not available, and stacked-crystals and layer-by-layer wafer-scale single-crystal growth are yet to be demonstrated. Significant efforts are being dedicated to the understanding of single-crystal growth by CVD through simulations 63 and experiments 51,64 . The growth of lateral heterostructures (Fig. 1d,e), as described above, will require a different approach. Seeding experiments performed up until now 64,65 will form the basis for future lateral heterostructures. Seeding of both graphene and TMD films has already been demonstrated and it is not difficult to imagine a process in which sequential films can be grown in a similar way to ...
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... most important challenge, for devices based on both lateral and vertical heterostructures, is the preparation of the basic mate- rials followed by their integration in the desired device structure. While vertical heterostructures, in principle, can be formed by direct growth (Fig. 1a) or by a transfer process for planar geometries (Fig. 1b), lateral heterostructures must be grown in place by some chemical means. At present, three methods are used or are under evaluation for the fabrication of 2D materials-based heterostruc- tures 58 : (1) layer-by-layer stacking via mechanical transfer of CVD- grown films and ...
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... most important challenge, for devices based on both lateral and vertical heterostructures, is the preparation of the basic mate- rials followed by their integration in the desired device structure. While vertical heterostructures, in principle, can be formed by direct growth (Fig. 1a) or by a transfer process for planar geometries (Fig. 1b), lateral heterostructures must be grown in place by some chemical means. At present, three methods are used or are under evaluation for the fabrication of 2D materials-based heterostruc- tures 58 : (1) layer-by-layer stacking via mechanical transfer of CVD- grown films and exfoliated natural or synthetic bulk-grown 2D materials; (2) ...
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... placement of 2D mate- rials via mechanical transfer is the only technique that has been successfully used to create heterostructures and heterostructure devices. The method has relied principally on the mechanical exfo- liation of bulk layered materials into atomically thin sheets 59 , but more recently the direct transfer of CVD-grown films (Fig. 1b) has also been used. The method has been extensively used for graphene, bilayer graphene, h-BN and TMDs to fabricate various stacked devices 60 . While transfer techniques of synthetic films or exfoli- ated layers from natural or synthetic bulk crystals have enabled the demonstration of many proof-of-principle stacked devices, allow- ...
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... and placement of the 2D films, many opportunities will emerge for the integration of these material structures in semiconductor manufac- turing flows. The ideal or preferred case would be to use MBE, CVD and ALE processes to create/grow in situ new heterostructures. However, it is envisioned that the growth of on-demand aligned heterostructures (Fig. 1a) using these techniques could be extremely difficult, particularly in the case of twisted layers (Fig. ...
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... in semiconductor manufac- turing flows. The ideal or preferred case would be to use MBE, CVD and ALE processes to create/grow in situ new heterostructures. However, it is envisioned that the growth of on-demand aligned heterostructures (Fig. 1a) using these techniques could be extremely difficult, particularly in the case of twisted layers (Fig. ...
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... in that wafer-scale single crystals are still not available, and stacked-crys- tals and layer-by-layer wafer-scale single-crystal growth are yet to be demonstrated. Significant efforts are being dedicated to the understanding of single-crystal growth by CVD through simula- tions 63 and experiments 51,64 . The growth of lateral heterostructures (Fig. 1d,e), as described above, will require a different approach. Seeding experiments performed up until now 64,65 will form the basis for future lateral heterostructures. Seeding of both graphene and TMD films has already been demonstrated and it is not dif- ficult to imagine a process in which sequential films can be grown in a similar way to ...
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... most important challenge, for devices based on both lateral and vertical heterostructures, is the preparation of the basic materials followed by their integration in the desired device structure. While vertical heterostructures, in principle, can be formed by direct growth (Fig. 1a) or by a transfer process for planar geometries (Fig. 1b), lateral heterostructures must be grown in place by some chemical means. Currently, three methods are used or under evaluation for the fabrication of 2D materials-based heterostructures [58]: (i) layer-by-layer stacking via mechanical transfer of CVD grown films and exfoliated ...
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... most important challenge, for devices based on both lateral and vertical heterostructures, is the preparation of the basic materials followed by their integration in the desired device structure. While vertical heterostructures, in principle, can be formed by direct growth (Fig. 1a) or by a transfer process for planar geometries (Fig. 1b), lateral heterostructures must be grown in place by some chemical means. Currently, three methods are used or under evaluation for the fabrication of 2D materials-based heterostructures [58]: (i) layer-by-layer stacking via mechanical transfer of CVD grown films and exfoliated natural or synthetic bulk grown 2D materials; (ii) direct ...
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... stacking or deterministic placement of 2D materials via mechanical transfer is the only technique that has been used to create heterostructures. The method has relied principally on the mechanical exfoliation of bulk layered materials into atomically thin sheets [59], but more recently the direct transfer of CVD-grown films (Fig. 1b) has also been used. The method has been extensively used for graphene, bi-layer graphene, h-BN, and TMDs to fabricate various stacked devices. While transfer techniques of synthetic films or exfoliated layers from natural or synthetic bulk crystals have enabled the demonstration of many proof-of-principle stacked devices, allowing ...
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... ideal or preferred case would be to use MBE, CVD and ALE processes to create/grow in-situ new heterostructures. However, it is envisioned that the growth of on-demand aligned heterostructures (see Fig.1a) using these techniques could be extremely difficult, particularly in the case of twisted layers (Fig.1c). ...
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... ideal or preferred case would be to use MBE, CVD and ALE processes to create/grow in-situ new heterostructures. However, it is envisioned that the growth of on-demand aligned heterostructures (see Fig.1a) using these techniques could be extremely difficult, particularly in the case of twisted layers (Fig.1c). ...
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... efforts are being dedicated to the understanding of single crystal growth by chemical vapour deposition through simulations and experiments [51] [64]. The growth of lateral heterostructures (see Fig. 1 d,e) as described above will require a different approach. Seeding experiments performed up until now [64][65] will form the basis for future lateral heterostructures. ...

Citations

... The recent development of van der Waals (vdW) heterostructures based on diverse combinations of two-dimensional (2D) crystals opened up possibilities to explore novel physical phenomena as well as device applications 1,2 . Here, much effort has been devoted to identify device architectures that maximally utilize unique properties emerging from hybrid forms of 2D vdW materials in non-equilibrium conditions [3][4][5] . For example, the junction configuration with few-layer 2D semiconductors or insulators sandwiched between graphene electrodes represents a promising platform from which phenomena such as the chiral quantum state 6,7 , giant tunneling magnetoresistance 8,9 , and negative differential resistance (NDR) 7,10-12 can be explored. ...
Article
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To enable the computer-aided design of vertically stacked two-dimensional (2D) van der Waals (vdW) heterostructure devices, we here introduce a non-equilibrium first-principles simulation method based on the multi-space constrained-search density functional formalism. Applying it to graphene/few-layer hBN/graphene field-effect transistors, we show that the negative differential resistance (NDR) characteristics can be produced not only from the gating-induced mismatch between two graphene Dirac cones in energy-momentum space but from the bias-dependent energetic shift of defect levels. Specifically, for a carbon atom substituted for a nitrogen atom (C N ) within inner hBN layers, the increase of bias voltage is found to induce a self-consistent electron filling of in-gap C N states, which in turn changes voltage drop profiles and produces symmetric NDR characteristics. With the C N placed on outer hBN layers, however, the pinning of C N states to nearby graphene significantly modifies device characteristics, demonstrating the critical impact of atomic details for 2D vdW devices.
... Low-dimensional materials have attracted considerable attention for their intriguing mechanical, electrical, optical, and physiochemical properties originating from the reduced dimensionality and quantum confinement effects 1 and also for the compatibility with device fabrication and integration and other useful functional applications. 2,3 As a large family, two-dimensional (2D) materials and devices have been intensively studied, and their various applications in the fields of physics, 4 chemistry, 5 materials, 6 and biology 7 have been explored. Quasione-dimensional (quasi-1D) materials are a newly arising topic in low-dimensional research, 8 although many of them have been discovered or synthesized for a long time. ...
Article
Quasi-one-dimensional (quasi-1D) materials are a newly arising topic in low-dimensional research. As a result of reduced dimensionality and enhanced anisotropy, the quasi-1D structure gives rise to novel properties and promising applications such as photodetectors. However, it remains an open question whether performance crossover will occur when the channel material is downsized. Here, we report on the fabrication and testing of photodetectors based on exfoliated quasi-1D BiSeI thin wires. Compared with the device on bulk crystal, a significantly enhanced photoresponse is observed, which is manifested by a series of performance parameters, including ultrahigh responsivity (7 [Formula: see text] 10 ⁴ A W ⁻¹ ), specific detectivity (2.5 [Formula: see text] 10 ¹⁴ Jones), and external quantum efficiency (1.8 [Formula: see text] 10 ⁷ %) when V ds = 3 V, [Formula: see text] = 515 nm, and P = 0.01 mW cm ⁻² . The conventional photoconductive effect is unlikely to account for such a superior photoresponse, which is ultimately understood in terms of the increased specific surface area and the photogating effect caused by trapping states. This work provides a perspective for the modulation of optoelectronic properties and performance in quasi-1D materials.
... Two-dimensional (2D) materials represent one of the most promising technology for next-generation beyond-CMOS electronics [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. Their layered structure makes them suitable to realize field-effect transistors (FETs) with atomically thin channels. ...
Article
Two-dimensional (2D) materials are recognized as a promising beyond-CMOS technology thanks to their attractive electrical and mechanical properties, which make them particularly suitable for flexible electronics. This work investigates molybdenum disulfide (MoS2) based field-effect transistors (FETs) fabricated on paper substrate to design hardware-security primitives such as Physically Unclonable Functions (PUFs). Circuit simulations have been performed by using a look-up-table (LUT) based Verilog-A model calibrated on electrical measurements of fabricated devices. Obtained results prove the potential of paper-based MoS2 FETs as building blocks for next-generation flexible electronics in the field of hardware security.
... Owing to the critical role in advanced manufacturing, many researchers have attempted to exploit the opportunity of producing microand nanodevices in the past decades since the discovery of graphene in 2004 [7][8][9][10]. Particularly, the nanodevices based on two-dimensional (2D) materials have attracted great attention owing to their extraordinary properties, thus becoming the focus of research in the field of nanodevice manufacturing [11][12][13][14][15][16]. Considering material structure for nanodevices, the hybrid systems consisting of 2D and organic semiconductor thin films have sparked new research directions [17][18][19][20][21], and the combination of the advantages of both 2D and organic materials [22][23][24] has been widely con-sidered to be promising for developing the novel nanodevices in the future. ...
Article
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The advanced manufacturing of ultra-thin-film devices, especially the nano-semiconductor products, has drawn a significant research interest over the past decades. In this field, monitoring the properties and thickness of the semiconductor layers is of paramount importance, which has significant impact on the device quality. In this study, an in situ monitoring scheme for manufacturing of nanodevices has been proposed, which is able to accurately analyse the optical absorption properties of the semiconductor layers of varying thickness in nanodevices. The in situ reflectance spectral analysis of monolayer, bilayer, and bulk-phase samples confirms the practicability and reliability of the monitoring scheme. The findings reported in this study form the basis for the advanced manufacturing of nano- and sub-nanodevices in the future.
... As compared with conventional nanomaterials (nanosheets, nanofibers and quantum dots) that may possess unsaturated dangling bonds, the atomic-scale LDMs are characterized by terminated surfaces, which are chemically inert and can thus confine the intrinsic properties and functionalities of the LDMs [9,10]. In recent years, with the aid of state-of-the-art high-throughput first principles calculations, a multitude of atomic-scale LDM candidates have been discovered, predominantly in the form of two-dimensional (2D) atomic layers [11][12][13][14][15][16][17][18][19][20][21]. ...
Article
The past decades have witnessed an exponential growth in the discovery of low-dimensional materials (LDMs), benefited from our unprecedented capabilities in characterizing their structure and chemistry with the aid of advanced computational techniques. Recently, the success of two-dimensional (2D) compounds has motivated extensive research into 1D atomic chains. Here we present a methodology for topological classification of structural blocks in bulk crystals based on graph theory, leading to the identification of exfoliable 1D atomic chains and their categorization into a variety of chemical families. A subtle interplay is revealed between the prototypical 1D structural motifs and their chemical space. Leveraging the structure graphs, we elucidate the self-passivation mechanism of 1D compounds imparted by lone electron pairs, and reveal the dependence of electronic band gap on the cationic percolation network formed by connections between structure units. This graph-theory-based formalism can serve as a source of stimuli for future design of LDMs.
... An ideal 2D material transfer technique should have the characteristics of being fast, universal, reproducible, scalable, cost-effective, and damage-free. 155 Recently, new breakthroughs in the direct growth of 2D materials (e.g., graphene) on insulating substrates (Figure 8a) 155 or the direct growth of 2D heterostructures (e.g., graphene on grown-hBN or hBN on grown-graphene) ( Figure 8b−d) 441 without the wet/dry transfers have made important progress. ...
... The transistors are operated by grounding the source and applying a drain voltage; among those, the source normally utilizes multiple low-dimensional materials such as a graphene−Si junction, metal−Si Schottky junction, or graphene−semiconductor heterojunction to offer several unique advantages (e.g., ultrathin, medium price, fabrication at room temperature, and good stability) for the d e s i g n o f n e x t -g e n e r a t i o n t r a n s i s t o r s ( T a b l e 6). 31,34,192,370,373,378,379,389,441,449,541,757−791 In recent advances, there are some typical transistor types such as the FET ( Figure 35), 441 tunnel-field-effect transistor (TFET) (Figure 35), 441 high-speed transistor, HETs, vertical molecular tunneling transistor, gas-channel and ion-channel transistors, ferroelectric field-effect transistors, negative capacitance field-effect transistors (NC-FETs), and barristors 441 (Figure 35). 6.2.7.1. ...
... The transistors are operated by grounding the source and applying a drain voltage; among those, the source normally utilizes multiple low-dimensional materials such as a graphene−Si junction, metal−Si Schottky junction, or graphene−semiconductor heterojunction to offer several unique advantages (e.g., ultrathin, medium price, fabrication at room temperature, and good stability) for the d e s i g n o f n e x t -g e n e r a t i o n t r a n s i s t o r s ( T a b l e 6). 31,34,192,370,373,378,379,389,441,449,541,757−791 In recent advances, there are some typical transistor types such as the FET ( Figure 35), 441 tunnel-field-effect transistor (TFET) (Figure 35), 441 high-speed transistor, HETs, vertical molecular tunneling transistor, gas-channel and ion-channel transistors, ferroelectric field-effect transistors, negative capacitance field-effect transistors (NC-FETs), and barristors 441 (Figure 35). 6.2.7.1. ...
Article
Full-text available
A grand family of two-dimensional (2D) materials and their heterostructures have been discovered through the extensive experimental and theoretical efforts of chemists, material scientists, physicists, and technologists. These pioneering works contribute to realizing the fundamental platforms to explore and analyze new physical/chemical properties and technological phenomena at the micro–nano–pico scales. Engineering 2D van der Waals (vdW) materials and their heterostructures via chemical and physical methods with a suitable choice of stacking order, thickness, and interlayer interactions enable exotic carrier dynamics, showing potential in high-frequency electronics, broadband optoelectronics, low-power neuromorphic computing, and ubiquitous electronics. This comprehensive review addresses recent advances in terms of representative 2D materials, the general fabrication methods, and characterization techniques and the vital role of the physical parameters affecting the quality of 2D heterostructures. The main emphasis is on 2D heterostructures and 3D-bulk (3D) hybrid systems exhibiting intrinsic quantum mechanical responses in the optical, valley, and topological states. Finally, we discuss the universality of 2D heterostructures with representative applications and trends for future electronics and optoelectronics (FEO) under the challenges and opportunities from physical, nanotechnological, and material synthesis perspectives.
... An abrupt doping profile is applied at the interface between the source or drain and the channel, while the contacts are assumed to be perfectly ohmic (no contact resistance). The TMD-metal contact resistance is currently one of the main limiting factors in 2D-based devices [52][53][54][55][56][57]. It is typically 10 to 100 times larger than in high-performance Si FinFETs [58], but recent experimental studies have shown that it could be reduced in the order of 100's Ω · µm, which is a value better compatible with practical applications [59]. ...
Article
Full-text available
The encapsulation of single-layer 2D materials within hBN has been shown to improve the mobility of these compounds. Nevertheless, the interplay between the semiconductor channel and the surrounding dielectrics is not yet fully understood, especially their electron–phonon interactions. Therefore, here, we present an ab initio study of the coupled electrons and phonon transport properties of MoS2-hBN devices. The characteristics of two transistor configurations are compared to each other: one where hBN is treated as a perfectly insulating, non-vibrating layer and one where it is included in the ab initio domain as MoS2. In both cases, a reduction of the ON-state current by about 50% is observed as compared to the quasi-ballistic limit. Despite the similarity in the current magnitude, explicitly accounting for hBN leads to additional electron–phonon interactions at frequencies corresponding to the breathing mode of the MoS2-hBN system. Moreover, the presence of an hBN layer around the 2D semiconductor affects the Joule-induced temperature distribution within the transistor.
... This is also the principle reason for their suitability as a channel material in extremely scaled transistors. 59,60 The suitability of vdW 2D channels for post-Si electronics or "more than Moore" electronics is well known and extensively discussed in reviews exclusively focused on transistor devices. [59][60][61] Here, we will focus on the following question: What does this electrostatic or gate tunability enable in 2D semiconductor devices that is unattainable or not demonstrated yet in other known semiconductors? ...
... 59,60 The suitability of vdW 2D channels for post-Si electronics or "more than Moore" electronics is well known and extensively discussed in reviews exclusively focused on transistor devices. [59][60][61] Here, we will focus on the following question: What does this electrostatic or gate tunability enable in 2D semiconductor devices that is unattainable or not demonstrated yet in other known semiconductors? ...
Article
The interest in two-dimensional and layered materials continues to expand, driven by the compelling properties of individual atomic layers that can be stacked and/or twisted into synthetic heterostructures. The plethora of electronic properties as well as the emergence of many different quasiparticles, including plasmons, polaritons, trions, and excitons with large, tunable binding energies that all can be controlled and modulated through electrical means, has given rise to many device applications. In addition, these materials exhibit both room-temperature spin and valley polarization, magnetism, superconductivity, piezoelectricity that are intricately dependent on the composition, crystal structure, stacking, twist angle, layer number, and phases of these materials. Initial results on graphene exfoliated from single bulk crystals motivated the development of wide-area, high purity synthesis and heterojunctions with atomically clean interfaces. Now by opening this design space to new synthetic two-dimensional materials “beyond graphene,” it is possible to explore uncharted opportunities in designing novel heterostructures for electrically tunable devices. To fully reveal the emerging functionalities and opportunities of these atomically thin materials in practical applications, this review highlights several representative and noteworthy research directions in the use of electrical means to tune these aforementioned physical and structural properties, with an emphasis on discussing major applications of beyond graphene 2D materials in tunable devices in recent years and an outlook of what is to come in the next decade.
... Transition metal dichalcogenides (TMDCs) are well suited for post-silicon CMOS or for an integration with CMOS technology because i) they provide much higher mobility than silicon in the case of ultrathin channel layers required by aggressive scaling, and ii) the weak van der Waals interaction between stacked layers is useful for 3D integration of transistors [14]- [16]. Some recent experimental results are very promising in view of their use in analog neural networks: [17]. ...
Article
Full-text available
Embedding advanced cognitive capabilities in battery-constrained edge devices requires specialized hardware with new circuit architecture and – in the medium/long term - new device technology. We evaluate the potential of recently investigated devices based on 2D materials for the realization of analog deep neural networks, by comparing the performance of neural networks based on the same circuit architecture using three different device technologies for transistors and analog memories. As a reference result, it is included in the comparison also an implementation on a standard 0.18 μm CMOS technology. Our architecture of choice makes use of current-mode analog vector-matrix multipliers based on programmable current mirrors consisting of transistors and floating-gate non-volatile memories. We consider experimentally demonstrated transistors and memories based on a monolayer Molibdenum Disulfide channel and ideal devices based on heterostructures of multilayer-monolayer PtSe2. Following a consistent methodology for device-circuit co-design and optimization, we estimate layout area, energy efficiency and throughput as a function of the equivalent number of bits (ENOB), which is strictly correlated to classification accuracy. System-level tradeoffs are apparent: for a small ENOB experimental MoS2 floating-gate devices are already very promising; in our comparison a larger ENOB (7 bits) is only achieved with CMOS, signaling the necessity to improve linearity and electrostatics of devices with 2D materials.
... 2D materials to facilitate functional heterostructure devices. Features of this approach include; adding some functionality into such 2D structures [26][27][28], combining into nanocomposites to optimize many inherent properties such as optical absorption etc. [29,30] and, stacking them vertically layer-by-layer or arrange laterally by seamlessly stitched in-plane heterojunctions [31][32][33]. ...