Mauricio Terrones

As modern society enters the information age, the demand for electromagnetic pollution protection by humans has become increasingly high. Electromagnetic functional materials are becoming an active research topic in materials science, and fortunately carbon-based electromagnetic wave interference (EMI) shielding and microwave absorption (MA) materials, clearly outstand among all electromagnetic functional materials [1]. Therefore, Mao-Sheng Cao and Mauricio Terrones organized this virtual special issue (VSI) entitled" Carbon-based Electromagnetic Multifunctional Materials and Devices", which focuses on EMI shielding and MA materials with a broad range of materials combinations. This VSI reports original research accounts or reviews from more than 60 groups from 7 countries, showcasing the preparation and fabrication of EMI and MA materials, morphology and multidimensional structure fabrication …

Provided are compositions that include at least one two-dimensional layer of an inorganic compound and at least one layer of an organic compound in the form of one or more polypeptides. Methods of making and using the materials are provided. The organic layer contains one or more polypeptides, each of which have alternating repeats of crystallite-forming subsequences and amorphous subsequences. The crystallite-forming subsequences form crystallites comprising stacks of one or more β-sheets. The amorphous subsequences form a network of hydrogen bonds. A method includes i) combining one or more polypeptides with an inorganic material and an organic solvent, and ii) depositing one or more polypeptides, the inorganic material and the organic solvent onto a substrate. These steps can be repeated to provide a composite material that is a multilayer composite material. The composite materials can …

The capacity to manipulate magnetization in 2D dilute magnetic semiconductors (2D‐DMSs) using light, specifically in magnetically doped transition metal dichalcogenide (TMD) monolayers (M‐doped TX2, where M = V, Fe, and Cr; T = W, Mo; X = S, Se, and Te), may lead to innovative applications in spintronics, spin‐caloritronics, valleytronics, and quantum computation. This Perspective paper explores the mediation of magnetization by light under ambient conditions in 2D‐TMD DMSs and heterostructures. By combining magneto‐LC resonance (MLCR) experiments with density functional theory (DFT) calculations, we show that the magnetization can be enhanced using light in V‐doped TMD monolayers (e.g., V‐WS2, V‐WSe2). This phenomenon is attributed to excess holes in the conduction and valence bands, and carriers trapped in magnetic doping states, mediating the magnetization of the semiconducting …

F49. 00004: High-throughput computationally-driven discovery and experimental realization of a new quantum defect in WS 2*

Point defects in two-dimensional materials are of key interest for quantum information science. However, the space of possible defects is immense, making the identification of high-performance quantum defects extremely challenging. Here, we perform high-throughput (HT) first-principles computational screening to search for promising quantum defects within WS 2, which present localized levels in the band gap that can lead to bright optical transitions in the visible or telecom regime. Our computed database spans more than 700 charged defects formed through substitution on the tungsten or sulfur site. We found that sulfur substitutions enable the most promising quantum defects. We computationally identify the neutral cobalt substitution to sulfur (Co ) as very promising and fabricate it with scanning tunneling microscopy (STM). The Co electronic structure measured by STM agrees with first principles and showcases an attractive new quantum defect. Our work shows how HT computational screening and novel defect synthesis routes can be combined to design new quantum defects.

Non-layered transition metal carbides (TMCs) and layered transition metal dichalcogenides (TMDs) are two well-studied material families that have individually received considerable attention over the past century. In recent years, with the shift towards two-dimensional materials and heterostructures, a field has emerged that is focused on the structure and properties of TMC/TMD heterostructures, which through chemical conversion exhibit diverse types of heterostructure configuration that host coupled 2D–3D interfaces, giving rise to exotic properties. In this Review, we highlight experimental and computational efforts to understand the routes to fabricate TMC/TMD heterostructures. Furthermore, we showcase how controlling these heterostructures can lead to emergent electronic transport, optical properties and improved catalytic properties.

Two-dimensional dilute magnetic semiconductors has been recently reported in semiconducting transition metal dichalcogenides by the introduction of spin-polarized transition metal atoms as dopants. This is the case of vanadium-doped WS and WSe monolayers, which exhibits a ferromagnetic ordering even above room temperature. However, a broadband characterization of their electronic band structure and its dependence on vanadium concentration is still lacking. Therefore, here we perform power-dependent photoluminescence, resonant four-wave mixing, and differential reflectance spectroscopy to study the optical transitions close to the A exciton energy of vanadium-doped WS monolayers with distinct concentrations. Instead of a single A exciton peak, vanadium-doped samples exhibit two photoluminescence peaks associated with transitions to occupied and unoccupied bands. Moreover, resonant Raman spectroscopy and resonant second-harmonic generation measurements revealed a blueshift in the B exciton but no energy change in the C exciton as vanadium is introduced in the monolayers. Density functional theory calculations showed that the band structure is sensitive to the Hubbard correction for vanadium and several scenarios are proposed to explain the two photoluminescence peaks around the A exciton energy region. Our work provides the first broadband optical characterization of these two-dimensional dilute magnetic semiconductors, shedding light on the novel electronic features of WS monolayers which are tunable by the vanadium concentration.

D16. 00007: Low temperature electronic transport properties of ultrathin, single crystal WC and W 2 C nanoplates*