jinzhitong

Nature Materials, Published online: 03 June 2021; doi:10.1038/s41563-021-01026-y

Silicon is a light element with high lattice inversion symmetry, and so is not expected to possess a substantial spin–orbit interaction (SOI), which is desirable for spintronics. Here, a silicon-based heterostructure is demonstrated to have a gate-tuneable Rashba-type SOI.

This work demonstrates the synthesis and characterization of electrical and optoelectronic properties of a novel ternary 2D layered material (2DLM) FePSe₃ and its FET-type photodetector by an optimized CVT method. A wide photocurrent response from visible to near-infrared is achieved, highlighting the opportunity of ternary 2DLM in photodetection of continuum spectrum.

Abstract

The preparation of ternary 2D layered material (2DLM) FePSe₃ and field-effect transistor (FET) type photodetector are investigated. By advancing an optimized chemical vapor transport method, bulk crystal FePSe₃ is synthesized within several growth hours instead of routinely required weeks, from which 2DLM FePSe₃ flakes with a thickness of ≈22.0 nm and high crystalline quality are obtained through mechanical exfoliation. Ohmic contacts for FET structure with good linear conductivity and thermal stability are implemented through the combination of electron-beam lithography and thermal evaporation techniques. Transfer characteristics prove the p-type conductivity of the 2DLM FePSe₃ channel. The transistor devices exhibit good performance at 637 nm with a detectivity of 1.17 × 10⁷ Jones. More importantly, a wide photocurrent spectrum from visible (450 nm) to near-infrared (940 nm) of ternary 2DLMs is observed, which is attributed to the improvement of crystal quality of 2DLM, relatively low surface defect states, and high-performance Ohmic electrodes. This work promotes the development of ternary 2DLM and photodetector that are still in their infancy towards continuous broad-spectrum technology.

Nature Physics, Published online: 03 June 2021; doi:10.1038/s41567-021-01283-3

Author Correction: Strong correlations and orbital texture in single-layer 1T-TaSe₂

Nature Nanotechnology, Published online: 03 June 2021; doi:10.1038/s41565-021-00921-4

MoS2/hBN/graphene van der Waals heterostructures with a clean interface and optimized barrier height and gate coupling ratio enable the realization of ultrafast non-volatile flash memory.

Nature Nanotechnology, Published online: 03 June 2021; doi:10.1038/s41565-021-00916-1

The existence of interlayer excitons with strong oscillator strength in bilayer MoS2 enables their electrical manipulation up to room temperature.

Nature Materials, Published online: 01 June 2021; doi:10.1038/s41563-021-00997-2

Author Correction: Chern insulators, van Hove singularities and topological flat bands in magic-angle twisted bilayer graphene

Nature Chemistry, Published online: 01 June 2021; doi:10.1038/s41557-021-00729-8

Chirality is fundamental to chemistry, molecular biology and photonics, but chirality itself is not often in the spotlight. Lewis E. MacKenzie and Patrycja Stachelek report on the 2021 Chiral Materials meeting, which explored how chirality manifests in functional materials, and how it can lead to new technological applications.

Nature, Published online: 02 June 2021; doi:10.1038/s41586-021-03541-z

Optical experiments on WSe2/MoSe2 heterobilayers reveal signatures of moiré trions, including interlayer emission with sharp lines and a complex charge-density dependence, features that differ markedly from those of conventional trions.

Nature, Published online: 02 June 2021; doi:10.1038/s41586-021-03488-1

Single-crystal monolayer hexagonal boron nitride is unexpectedly tough owing to its asymmetric lattice structure, which facilitates repeated crack deflection, crack branching and edge swapping, enhancing energy dissipation.

A new-type magnetic-sensitive crack sensor is designed by depositing graphene nanosheets upon a flexible magnetic film through a facial infrared drying technique. Such a sensor can obtain an ultra-high sensitivity with relative resistance change of 4.0 × 10¹⁰ at room temperature and an excellent cycling stability over 6000 cycles toward a moderate magnetic field.

Abstract

Flexible magnetic field sensors attract significant interests in magnetic detection and flexible electronics. However, two challenges, low sensitivity, and limited working range, impede their practical application. Herein, a new type of magnetic-sensitive crack sensor (M-CS) by depositing graphene nanosheets upon a flexible magnetic film through a facial infrared drying technique is reported. The M-CS exhibits an ultrahigh sensitivity (relative resistance change up to 4.0 × 10¹⁰) toward a moderate magnetic field of 43 mT at room temperature. In addition, the M-CS shows a long cycling stability over 10 000 cycles. Such a superior sensitivity is attributed to physically cutting/recovering the pathways of electron transport through nanosheets’ separation/contact. Diverse experimental parameters, such as the concentration of graphene solution and the thickness of bottom magnetic substrates, have been tailored to improve the magnetic sensitivity of M-CS. Furthermore, the array of M-CSs with different relative resistance change can be used as the cipher key to recognize aimed magnetic signal without contact. It is believed that the M-CS with an ultrahigh magnetic sensitivity at operational condition and long-term stability could benefit the development of magneto-sensitive sensors, and exploit the application of 2D materials in flexible electronic devices.

A detailed low-frequency noise analysis of bilayer MoS₂ transistors fabricated on paper substrate with inkjet-printed dielectrics and contacts is presented. The extracted noise figure of merit is comparable to those reported for monolayer and bilayer MoS₂ transistors fabricated on SiO₂ using conventional techniques. These results are promising for the future development of low noise flexible electronics based on 2D materials.

Abstract

1/f noise represents the dominant source of noise in the low-frequency range in several physical systems, including field-effect transistors. Its investigation can provide very important information on the fabrication process, highlighting the steps that are more prone to the introduction of defects. Here, 1/f noise in bilayer MoS₂ transistors on paper with inkjet-printed Ag contacts and hBN dielectric is investigated. These devices are promising building blocks for future low-cost, flexible, and easily recyclable disposable electronics. The analysis of 1/f noise, performed following Hooge's empirical approach, results in a Hooge parameter ≈1–10, which is comparable to those reported for bilayer MoS₂ transistors on SiO₂. The present results indicate that the noise properties of the investigated devices are stable against substrate bending and are mainly determined by the printing of the dielectric, while not being sensibly affected by the use of the paper substrate. These results are promising for the further development of low noise 2D material-based flexible electronics on paper.

Black phosphorus (BP), with prominent features such as high carrier mobility and easily modulated band structure, fills the deficiencies of graphene and transition metal dichalcogenides. Starting from the introduction of BP's crystal structure, this work reviews the doping strategies, van der Waals heterojunction, and contact engineering thickness control technology in bandgap adjustment and performance improvement of BP-field effect transistor.

Abstract

Black phosphorus (BP), an emerging crystal material with prominent features such as high carrier mobility and easily modulated band structure, fills the deficiencies of graphene and transition metal dichalcogenides. It has become a key component of 2D materials. The biggest advantage of BP is reflected in the fixed and direct energy band structure. Starting from the introduction of BP's crystal structure, this work reviews the important role of doping strategies, van der Waals heterojunction, and contact engineering thickness control technology in bandgap adjustment and performance improvement of BP field effect transistors. The focus is to put on the enhanced performance of electronic devices in high mobility, fast response speed, wide spectral range, low power consumption, and stronger stability caused by bandgap modulation. These methods cover from advanced technology to a wide range of electrical and optoelectronic progress in recent years, showing a booming development trend. In addition, considering the breakthrough of BP in new physics and application prospects, the potential applications of the active field are highlighted in this work.

Nature Electronics, Published online: 25 May 2021; doi:10.1038/s41928-021-00584-y

A three-phase system that is composed of a ferroelectric Na0.5Bi0.5TiO3 matrix in which ferrimagnetic NiFe2O4 nanocolumns coated with antiferromagnetic p-type NiO are embedded exhibits self-biased magnetoelectric switching at room temperature.

Nature Electronics, Published online: 25 May 2021; doi:10.1038/s41928-021-00586-w

Band-engineered van der Waals heterostructures that block dark current without suppressing photocurrent can be used to build detectors with high room-temperature detectivity for visible light and blackbody infrared light.

Nature, Published online: 26 May 2021; doi:10.1038/s41586-021-03501-7

Nanoscale imaging of edge currents in charge-neutral graphene shows that charge accumulation can explain various exotic nonlocal transport measurements, bringing into question some theories about their origins.

Nature Materials, Published online: 20 May 2021; doi:10.1038/s41563-021-01004-4

Angle-resolved photoemission spectroscopy is used to track the evolution of the electronic band structure of TaSe3 across a strain-driven topological phase transition.