Jing Zhang

Nature Nanotechnology, Published online: 07 December 2020; doi:10.1038/s41565-020-00821-z

Author Correction: Layer-controlled single-crystalline graphene film with stacking order via Cu–Si alloy formation

Nature Nanotechnology, Published online: 21 December 2020; doi:10.1038/s41565-020-00816-w

Manipulation of multiple connected quantum objects is mandatory for any scalable quantum information platform. Based on finely tuned virtual gate control, the integration of nearest-neighbour coupled semiconductor quantum dots in a 3 × 3 array enables 2D coherent spin control.

In article number 2004896, John T. L. Thong, Jing Wu, and co‐workers investigate thermoelectric transport in novel 2D palladium diselenide (PdSe₂) with a low‐symmetry pentagonal lattice. Due to its sensitive dependence on the interlayer coupling originating from the special lattice structure, the thermoelectric performance can be largely enhanced. The high band convergence and quantum confinement through thickness engineering advance and broaden the applications of thermoelectric such as in soft robotics, health monitoring, and human‐machine interfaces.

Two structural phases, 1T and 2H of TMDC alloy Mo_0.5Nb_0.5Se₂ are synthesized and characterized by various methods. 2H‐Mo_0.5Nb_0.5Se₂ is found to be metallic and 1T‐Mo_0.5Nb_0.5Se₂ is semiconducting, with a 0.42–0.58 eV bandgap at 77 K. Electron diffraction patterns and density‐function‐theory calculations reveal that the nearly commensurate charge density wave phase in 1T phase is the reason for the bandgap opening.

Abstract

Bandgap engineering plays a critical role in optimizing the electrical, optical and (photo)‐electrochemical applications of semiconductors. Alloying has been a historically successful way of tuning bandgaps by making solid solutions of two isovalent semiconductors. In this work, a novel form of bandgap engineering involving alloying non‐isovalent cations in a 2D transition metal dichalcogenide (TMDC) is presented. By alloying semiconducting MoSe₂ with metallic NbSe₂, two structural phases of Mo_0.5Nb_0.5Se₂, the 1T and 2H phases, are produced each with emergent electronic structure. At room temperature, it is observed that the 1T and 2H phases are semiconducting and metallic, respectively. For the 1T structure, scanning tunneling microscopy/spectroscopy (STM/STS) is used to measure band gaps in the range of 0.42–0.58 at 77 K. Electron diffraction patterns of the 1T structure obtained at room temperature show the presence of a nearly commensurate charge density wave (NCCDW) phase with periodic lattice distortions that result in an uncommon 4 × 4 supercell, rotated approximately 4° from the lattice. Density‐functional‐theory calculations confirm that local distortions, such as those in a NCCDW, can open up a band gap in 1T‐Mo_0.5Nb_0.5Se₂, but not in the 2H phase. This work expands the boundaries of alloy‐based bandgap engineering by introducing a novel technique that facilitates CDW phases through alloying.

A simple large‐scale methodology for the formation of vertically aligned molybdenum disulphide (VA‐MoS₂) is shown to be used in memristive devices. The resistive switching devices are formed by the fabrication of vertical Ag/VA‐MoS₂/Si heterostructures. Such devices exhibit a very promising memristive behavior, including high operation temperatures (up to 350 °C), and photoactive characteristics.

Abstract

Memristive devices have drawn considerable research attention due to their potential applications in non‐volatile memory and neuromorphic computing. The combination of resistive switching devices with light‐responsive materials is considered a novel way to integrate optical information with electrical circuitry. On the other hand, 2D materials have attracted substantial consideration, thanks to their unique crystal structure, as reflected in their chemical and physical properties. Although not the major focus, van der Waals solids are proven to be potential candidates in memristive devices. In this scheme, the majority of the resistive switching devices are implemented on planar flakes, obtained by mechanical exfoliation. Here a facile and robust methodology is utilized to grow large‐scale vertically aligned MoS₂ (VA‐MoS₂) films on standard silicon substrates. Memristive devices with the structure silver/VA‐MoS₂/Si are shown to have low set‐ON voltages (<0.5 V), large‐retention times (>2 × 10⁴ s), and high thermal stability (up to 350 °C). The proposed memristive device also exhibits long term potentiation/depression (LTP/LTD) and photo‐active memory states. The large‐scale fabrication, together with the low operating voltages, high thermal stability, light‐responsive behavior, and LTP/LTD, make this approach very appealing for real‐life non‐volatile memory applications.

In article number 2007458, Meganne Christian, Raffaello Mazzaro, and Vittorio Morandi analyze the bioinspired design of graphene‐based materials. The molecular structure of graphene resembles a natural honeycomb; moreover, thanks to the versatility of this amazing 2D material, it can also be shaped into honeycomb‐like microstructures with wide‐ranging applications such as next‐generation electronics and sensing. Honeycomb is just one of the myriad natural structures, functions, and processes that can be used as inspiration for exciting new functional materials based on graphene.

All-optical modulation with two-dimensional (2D) layered materials are becoming an indispensable tool in a variety of applications due to their superior performance in photonics and optoelectronics. Here, we review recent progress demonstrating the application of optical modulators utilizing their nonlinear optical properties of 2D materials. We focus specially on transition metal dichalcogenides, black phosphorus, and MXenes. We discuss the fabrication and integrating procedure of the layered materials and highlight recent demonstrations of all-optical passive modulators for ultrashort pulse generation and thermo-optic switches that applied in versatile interferometers. We also conclude with an outlook exploring the future perspectives that may accelerate the practical applications in this vibrant field.

The intrinsic magnetism has long been pursued in two-dimensional (2D) materials down to one-atomic layer thickness. But only very recently, the intrinsic magnetism of monolayer CrI 3 , Fe 3 GeTe 2 , FePS 3 , VSe 2 and bilayer Cr 2 Ge 2 Te 6 are verified in experiment by optical measurement, Raman spectrum and conventional magnetism measurement. Among them, the intralayer exchange interaction of FePS 3 is antiferromagnetic while all the others are ferromagnetic. Most of the ferromagnetic orders in these materials are induce by super exchange interaction. Monolayer Fe 3 GeTe 2 and VSe 2 exhibit metallic character while all the others are semiconductor or insulator. Stable spontaneous magnetization can exist in these monolayer 2D materials because of their strong anisotropy. The anisotropy is mostly from the strong spin–orbit coupling of heavy atoms (CrI 3 , Cr

Semi-permeable membranes are important elements in water purification and energy generation applications, for which the atomic thickness and strength of graphene can enhance efficiency and permeation rate while maintaining good selectivity. Here, we show that an osmotic pressure difference forms across a suspended graphene membrane as a response to a sucrose concentration difference, providing evidence for its semi-permeability. This osmotic pressure difference is detected via the deflection of the graphene membrane that is measured by atomic force microscopy. Using this technique, the time dependence of this deflection allows us to measure the water permeation rate of a single 3.4 µ m diameter graphene membrane. Its value is close to the expected value of a single nanopore in graphene. The method thus allows one to experimentally study the semi-permeability of graphene membranes at the microscale when the leakage rate is minuscule. It can therefore find use in the develop...

Defects have a profound impact on the electronic and physical properties of crystals. For two-dimensional (2D) materials, many intrinsic point defects have been reported, but much remains to be understood about their origin. Using scanning transmission electron microscopy imaging, this study discovers various linear arrays of W-vacancy defects that are explained in the context of the crystal growth of coalesced, monolayer WS 2 . Atomistic-scale simulations show that vacancy arrays can result from steric hindrance of bulky gas-phase precursors at narrowly separated growth edges, and that increasing the edge separation leads to various intact and defective growth modes, which are driven by competition between the catalytic effects of the sapphire substrate and neighboring growth edge. Therefore, we hypothesize that the arrays result from combined growth modes, which directly result from film coalescence. The connections drawn here will guide future synthetic and processin...

Double charge polarity switching is observed in Sb‐doped SnSe with switchable substitution sites. Pure SnSe shows p‐type conduction, whereas the polarity of (Sn_{1− x} Sb _x )Se is switched to n‐type for 0.005 < x < 0.05, and then re‐switched to p‐type for x > 0.05, where the major Sb substitution site changes from Se (Sb_Se) to Sn site (Sb_Sn) with increasing x.

Abstract

Tin mono‐selenide (SnSe) is one of the most promising thermoelectric materials; however, it experiences difficulty in controlling the carrier polarity, which is inevitable for realizing p‐n homojunction devices. Herein, double switching of charge polarity in (Sn_{1− x} Sb _x )Se by varying x is reported; pure SnSe shows p‐type conduction, whereas the polarity of (Sn_{1− x} Sb _x )Se switches to n‐type conduction for 0.005 < x < 0.05, and then re‐switches to p‐type conduction for x > 0.05. The major Sb substitution site switches from the Se (Sb_Se) to Sn site (Sb_Sn) with increasing x. Sb_Sn (Sb³⁺ at Sn²⁺) works as a donor, but Sb_Se (Sb³⁻ at Se²⁻) does not produce a hole because of the Sb–Sb dimer formation. The mechanism of double polarity switching is explained by native p‐type conduction in pure SnSe due to Sn‐vacancy formation, whereas (Sn_{1− x} Sb _x )Se exhibits n‐type behavior due to conduction through the Sb_Se impurity band formed above the valence band maximum, and finally re‐switches to weak p‐type, where the Fermi level approaches the midgap level between the Sb_Se band and conduction band minimum. Clarification of the Sb doping mechanism will provide a crucial guide for developing more sophisticated doping routes for SnSe and high‐performance energy‐related devices.

2D CsPbBr₃/CdS flakes are achieved via epitaxial growth. The as‐synthesized heterostructures display high‐quality crystallization and strong interlayer coupling at the interface. Meanwhile, the device exhibits excellent excitonic photovoltaic effects, including large open‐circuit voltage (≈0.76 V), high power conversion efficiency (≈17.5%). In addition, a fast response time of 23 µs is achieved under zero bias for photodetection.

Abstract

P–n photovoltaic junctions are essential building blocks for optoelectronic devices for energy conversion. However, this photovoltaic efficiency has almost reached its theoretical limit. Here, a brand‐new excitonic photovoltaic effect in 2D CsPbBr₃/CdS heterostructures is revealed. These heterostructures, synthesized by epitaxial growth, display a clean interface and a strong interlayer coupling. The excitonic photovoltaic effect is a function of both the built‐in equilibrium electrical potential energy and the chemical potential energy, which is generated by the significant concentration gradient of electrons and holes at the heterojunction interface. Excitingly, this novel photovoltaic effect results in a large open‐circuit voltage of 0.76 V and a high power conversion efficiency of 17.5%. In addition, high photodetection performance, including a high photoswitch ratio (I _light/I _dark) of 10⁵ and a fast response rate of 23 µs are obtained. These findings provide a new platform for photovoltaic applications.

Multilayer graphene is transferred from both sides of the metal growth substrate. After hot lamination transfer to the polymer, partial metal etching forms an interfacial oxide layer between adjacent graphene films, promoting their clean separation via surface tension. The oxide layer composition is investigated, and optical transmittance and electronic transport measurements verify similar film quality for both transferred graphene films.

Abstract

A method for graphene transfer which is referred to as “bifacial transfer” that allows transfer of multilayer chemical vapor deposition (CVD) graphene from both sides of a native metal substrate, such as an as‐received nickel catalyst, is presented. In traditional transfer methods, the graphene on the “non‐preferred” side, that is, the bottom of the substrate, is removed with oxygen plasma before removal of the metal catalyst in etchant solution. Although this treatment prevents undesired aggregation of the graphene films, it fails to utilize both sides of CVD‐grown graphene. The bifacial transfer method reduces the cost of multilayer graphene by allowing the transfer of graphene from both sides of the substrate. The quality of graphene transferred from both sides onto target glass and polymer substrates is compared. The results of optical microscopy, confocal Raman spectroscopy, atomic force microscopy, and electronic transport measurements suggest that the quality of the multilayer graphene on the “non‐preferred” side does not differ significantly from that of the “preferred” side. This method will allow more efficient and cost‐effective use of graphene by doubling the usable graphene per area of growth substrate, and by eliminating the need for intermediate sacrificial transfer substrates such as poly(methyl methacrylate).

As a new emerging 2D material, Bi₂O₂Se has shown remarkable properties. Herein, an overview of the research progress for Bi₂O₂Se is provided. The turnability of structure/property, preparation methods, and various applications of 2D Bi₂O₂Se are all discussed in this report. Bi₂O₂Se exhibits excellent properties for potential applications in many areas.

Abstract

The study of 2D materials has been a significant and fascinating area, at least since the discovery of graphene. As one of the layered bismuth oxychalcogenides, bismuth oxyselenide (Bi₂O₂Se) has drawn a lot of attention recently. The study of Bi₂O₂Se was mainly focused on its thermoelectric performance until its ultrathin 2D structure came to the fore. New physical properties of Bi₂O₂Se were discovered along with the successful synthesis of 2D Bi₂O₂Se structures. Few‐layer Bi₂O₂Se exhibits ultrahigh mobility, outstanding stability, tunable bandgaps, and excellent mechanical properties, showing remarkable performance in electronics and optoelectronics. In this report, an overview of recent advances in Bi₂O₂Se research is provided, including structure/property modifications, synthetic methods, and practical applications. Theoretical and experimental results on bulk/few‐layer Bi₂O₂Se are both discussed in this report. Finally, the challenges and outlook for Bi₂O₂Se are evaluated based on current progress.

This review summarizes the synthetic routes and fundamental properties of functional 2D MXene, highlights the state‐of‐the‐art progresses of the versatile applications of functional 2D MXene, and presents the challenges and perspectives in these burgeoning fields. It is anticipated that this review will inspire more efforts toward fundamental research on new functional 2D MXene‐based devices for next‐generation systems.

Abstract

Similar to graphene and black phosphorus (BP), 2D transition metal carbides and nitrides (MXenes) are of great interest in a variety of fields, such as energy storage and conversion, sensors, electromagnetic interference (EMI) shielding, and photothermal therapy due to their excellent conductivity and hydrophilicity, large specific capacitance, high photothermal effect, and superior electrochemical performance. To further broaden applicable ranges beyond their existing boundaries and fully exploit these potentials, functional 2D MXene nanostructures in recent years have been rationally designed and developed by various approaches, such as doping strategies, surface functionalization, and hybridization, for next‐generation devices with the merits of low power consumption, intelligence, and high‐integration chips. This review provides an overview of the synthetic routes and fundamental properties of functional 2D MXene nanostructures, including surface‐modified 2D MXenes and mixed‐dimensional MXene‐based heterostructures, highlights the state‐of‐the‐art progress in the applications of functional 2D MXene nanostructures with regard to energy storage and conversion, catalysis, sensors, photodetectors, EMI shielding, degradation, and biomedical applications, and presents the challenges and perspectives in these burgeoning fields. It is hoped that this review will inspire more efforts toward fundamental research on new functional 2D MXene‐based devices to satisfy the growing requirements for next‐generation systems.

Eshelby twist in van der Waals nanowires creates twisted interfaces and associated moiré patterns that modulate the electronic structure and can cause correlated electron phenomena. Here, twist manipulation is demonstrated by realizing nanowires harboring continuously varying interlayer moirés and homojunctions connecting twisted and equilibrium‐stacked segments. These novel architectures provide versatile platforms for exploring twist effects in van der Waals crystals.

Abstract

Moiré patterns at van der Waals interfaces between twisted 2D crystals give rise to distinct optoelectronic excitations, as well as, narrowly dispersive bands responsible for correlated electron phenomena. Contrasting with the conventional, mechanically stacked planar twist moirés, recent work shows twisted van der Waals interfaces spontaneously formed in nanowires of layered crystals, where Eshelby twist due to axial screw dislocations stabilizes a chiral structure with small interlayer rotation. Here, the realization of tunable twist in germanium(II) sulfide (GeS) van der Waals nanowires is reported. Tapered nanowires host continuously variable interlayer twist. Homojunctions between dislocated (chiral) and defect‐free (achiral) segments are obtained by triggering the emission of axial dislocations during growth. Measurements across such junctions, implemented here using local absorption and luminescence spectroscopy, provide a convenient tool for detecting twist effects. The results identify a versatile system for 3D twistronics, probing moiré physics, and for realizing moiré architectures without equivalent in planar systems.

The concept of 0D–2D vertical single electron transistors is unveiled. It allows to combine the large Coulomb energy of nanoclusters with the electronic capabilities of a two‐dimensional channel acting both as bottom electrode and dielectric for gate control of the nanoclusters charge states. These findings open doors to unexplored architectures of multifunctional quantum devices based on mixed‐dimensional heterostructures.

Abstract

Mixed‐dimensional heterostructures formed by the stacking of 2D materials with nanostructures of distinct dimensionality constitute a new class of nanomaterials that offers multifunctionality that goes beyond those of single dimensional systems. An unexplored architecture of single electron transistor (SET) is developed that employs heterostructures made of nanoclusters (0D) grown on a 2D molybdenum disulfide (MoS₂) channel. Combining the large Coulomb energy of the nanoclusters with the electronic capabilities of the 2D layer, the concept of 0D–2D vertical SET is unveiled. The MoS₂ underneath serves both as a charge tunable channel interconnecting the electrode, and as bottom electrode for each v‐SET cell. In addition, its atomic thickness makes it thinner than the Debye screening length, providing electric field transparency functionality that allows for an efficient electric back gate control of the nanoclusters charge state. The Coulomb diamond pattern characteristics of SET are reported, with specific doping dependent nonlinear features arising from the 0D/2D geometry that are elucidated by theoretical modeling. These results hold promise for multifunctional single electron device taking advantage of the versatility of the 2D materials library, with as example envisioned spintronics applications while coupling quantum dots to magnetic 2D material, or to ferroelectric layers for neuromorphic devices.

Atomic‐scale engineering of 2D layered catalysts via a heteroepitaxial conversion process using metal‐organic chemical vapor deposition has proven to be very efficient in enhancing the quality of the electrocatalysts. The out‐of‐plane deformation of the 2D WS₂/WTe₂ heterostructure driven by lattice coherency could enhance intrinsic catalytic activity and long‐term durability of the electrocatalysts under continuous operation.

Abstract

The structural engineering of 2D layered materials is emerging as a powerful strategy to design catalysts for high‐performance hydrogen evolution reaction (HER). However, the ultimate test of this technology under typical operating settings lies in the reduced performance and the shortened lifespan of these catalysts. Here, a novel approach is proposed to design efficient and robust HER catalysts through out‐of‐plane deformation of 2D heterojunction using metal‐organic chemical vapor deposition. High‐yield, single‐crystalline WTe₂ nanobelts are used as an epitaxial template for their coherent conversion to WS₂. During the conversion process, the WTe₂/WS₂ heterostructure containing both lateral and vertical junctions are achieved by coherent heteroepitaxial stacking despite differences in symmetry. The lattice coherency drives out‐of‐plane deformation of heteroepitaxially grown WS₂. The increase in the effective surface area and decrease in the electron‐transfer resistance across the 2D heterojunctions in turn enhances the HER performance as well as the long‐term durability of these electrocatalysts.

Type III heterojunction diodes using 2D p‐MoTe₂/organic n‐type HAT‐CN and 2D p‐WSe₂/n‐MoO _x systems well‐demonstrate static and dynamic NDR behavior via electron–hole recombination, particularly showing LC oscillations which are attributed to their high peak‐to‐valley current ratio. Extended to an inverter circuit, p‐MoTe₂/n‐HAT‐CN diode enables multilevel inverter characteristics as monolithically integrated with p‐MoTe₂ channel field effect transistor.

Abstract

Among many of 2D semiconductor‐based devices, type III PN junction diodes are given special attentions due to their unique function, negative differential resistance (NDR). However, it has been found uneasy to achieve well‐matched type III PN junctions from 2D–2D van der Waals heterojunctions. Here, the authors present other alternatives of type III heterojunctions, using 2D p‐MoTe₂/organic n‐type dipyrazino[2,3‐f:2′,3′‐h]quinoxaline‐2,3,6,7,10,11‐hexacarbonitrile (HAT‐CN) and 2D p‐WSe₂/n‐MoO _x systems. Those junction diodes appear to well‐demonstrate static and dynamic NDR behavior via resonant tunneling and electron–hole recombination. Extended to an inverter circuit, p‐MoTe₂/n‐HAT‐CN diode enables multilevel inverter characteristics as monolithically integrated with p‐MoTe₂ channel field effect transistor. The same NDR diode shows dynamic LC oscillation behavior under a constant DC voltage, connected to an external inductor. From p‐WSe₂/n‐MoO _x oxide diode, similar NDR behavior to those of p‐MoTe₂/n‐HAT‐CN is again observed along with LC oscillations. The authors attribute these visible oscillation results to high peak‐to‐valley current ratios of their organic or oxide/2D heterojunction diodes.

The most‐up‐to date progress and cutting‐edge advances in the rational microstructure design of MXenes‐based materials for energy storage and conversion are comprehensively summarized with a focus on the interlayer structure design, interfacial functionalization, and the construction of heterojunctions. Existing challenges and perspectives for the future development of 2D MXene‐based nanostructures are highlighted.

Abstract

MXenes have attracted increasing attention due to their unique advantages, excellent electronic conductivity, tunable layer structure, and controllable interfacial chemistry. However, the practical applications of MXenes in energy storage devices are severely limited by the issues of torpid reaction kinetics, limited active sites, and poor material utilization efficiency. Herein, the most‐up‐to date advances in the rational microstructure design to enhance electrochemical reaction kinetics and energy storage performance of MXene‐based materials are comprehensively summarized. This review begins with the preparation and properties of MXenes, classified into fluorine‐containing acid etching and fluoride‐free etching approaches. Afterwards, the interlayer structure design and interfacial functionalization of MXenes with respect to interlayer spacing and porous structure, terminal groups, and surface defects are summarized. Then the focus turns to the construction of advanced MXene‐based heterojunctions based on in situ derivation and surface self‐assembly. Based on these microstructure modulating strategies, the state‐of‐the‐art progress of MXene‐based applications with respect to supercapacitors, alkali metal‐ion batteries, metal–sulfur batteries, and photo/electrocatalysis are highlighted. Finally, the critical challenges and perspectives for the future research of 2D MXene‐based nanostructures are highlighted, aiming to present a comprehensive reference for the design of MXene‐based electrodes for electrochemical energy storage.

Phase‐change materials (PCM) utilizing the rapid transition between amorphous and crystalline chalcogenides enable precise and reliable brain‐inspired computing in both electronic and photonic neural networks. The recent advances in PCM‐based neuromorphic devices, as well as the related physics and transition dynamics, are surveyed and discussed in this article.

Abstract

Traditional von Neumann computing architecture with separated computation and storage units has already impeded the data processing performance and energy efficiency, calling for emerging neuromorphic electronic and optical devices and systems which can mimic the human brain to shift this paradigm. Material‐level innovation has become the key component to this revolution of information technology. Chalcogenide phase‐change material (PCM) as a well‐acknowledged data‐storage medium is a promising candidate to tackle this challenge. In this review, the use of PCMs to implement artificial neurons and synapses from both the electronic and optical respects is discussed, and in particular, the structure–property physics and transition dynamics that enable such brain‐inspired and in‐memory computing applications are emphasized. Recent advances on the atomic‐level amorphous and crystalline structures, transition mechanisms, materials optimization and design, neural and synaptic devices, brain‐inspired chips, and computing systems, as well as the future opportunities of PCMs, are summarized and discussed.

Graphene‐based “hybrid carbons” films composed of a mix of AB‐stacked and turbostratic regions are produced by heat treating graphene oxide/poly(norepinephrine) composite films at 3000 °C. Due to their structure, these hybrid carbon films have larger ultimate tensile strength (1012 ± 146 MPa) and in‐plane electrical conductivity (1320 ± 159 S cm⁻¹) compared to AB‐stacked carbon films made from only graphene oxide.

Abstract

Graphene‐based hybrid carbons composed of a mix of AB‐stacked and turbostratic regions are reported. Macroscopic graphene films consisting of stacked graphenes are prepared using a liquid crystal graphene oxide dispersion. The graphene films are then infiltrated with bioinspired adhesives, catecholamines, and polymerized to obtain graphene/poly(catecholamine) composites. After heat treatment up to 3000 ºC, the composite films are transformed to have both AB‐stacked (mainly from graphene oxide) and turbostratic (mainly from poly(catecholamines)) structures, and exhibit significantly improved mechanical properties compared to the films having a predominant AB‐stacked structure made from only graphene oxide. They have almost twice the fracture strength (1012 ± 146 MPa) and ≈1.5× increase of both Young's modulus (21.87 ± 2.24 GPa) and strain‐to‐failure (8.91 ± 0.50%). In addition, the films have an in‐plane electrical conductivity as high as 1320 ± 159 S cm⁻¹. Such hybrid‐carbon films with the indicated mechanical and electrical properties have many promising uses, such as for light‐weight structural materials, and in flexible electronics such as for wearable heaters or in sensing electrodes.

Nature Nanotechnology, Published online: 14 December 2020; doi:10.1038/s41565-020-00808-w

Graphene–insulator–metal heterostructures show three orders of magnitude enhancement of the third-harmonic generation with respect to the bare graphene case.

Nature Nanotechnology, Published online: 04 December 2020; doi:10.1038/s41565-020-00811-1

This Review provides an overview of the current understanding of the physics of organic–inorganic two-dimensional halide perovskites.