A5004506255- Graphene research and applications
- 2D Materials and Applications
- MXene and MAX Phase Materials
- Carbon Nanotubes in Composites
- Boron and Carbon Nanomaterials Research
- Diamond and Carbon-based Materials Research
- Advancements in Battery Materials
- Topological Materials and Phenomena
- Machine Learning in Materials Science
- Supercapacitor Materials and Fabrication
- Electronic and Structural Properties of Oxides
- Ga2O3 and related materials
- Electrocatalysts for Energy Conversion
- Perovskite Materials and Applications
- Surface and Thin Film Phenomena
- Metal and Thin Film Mechanics
- Advanced Thermoelectric Materials and Devices
- Chalcogenide Semiconductor Thin Films
- Nanopore and Nanochannel Transport Studies
- Intermetallics and Advanced Alloy Properties
- Thin-Film Transistor Technologies
- Semiconductor materials and devices
- Inorganic Chemistry and Materials
- Multiferroics and related materials
- Nanomaterials and Printing Technologies
Shanghai Jiao Tong University
2018-2023
Michigan State University
2011-2022
University of California, Santa Barbara
2016-2020
University of California System
2017-2018
Santa Barbara City College
2017-2018
Nankai University
2018
Changchun University of Science and Technology
2016
Fudan University
2013-2015
Aalto University
2010-2012
Russian Academy of Sciences
2010
Preceding the current interest in layered materials for electronic applications, research 1960's found that black phosphorus combines high carrier mobility with a fundamental band gap. We introduce its counterpart, dubbed few-layer phosphorene, as new 2D p-type material. Same graphene and MoS2, phosphorene is flexible can be mechanically exfoliated. find to stable and, unlike graphene, have an inherent, direct appreciable band-gap depends on number of layers. Our transport studies indicate...
We investigate a previously unknown phase of phosphorus that shares its layered structure and high stability with the black allotrope. find in-plane hexagonal bulk layer stacking this structure, which we call "blue phosphorus," to be related graphite. Unlike graphite phosphorus, blue displays wide fundamental band gap. Still, it should exfoliate easily form quasi-two-dimensional structures suitable for electronic applications. study likely transformation pathway from discuss possible ways...
Based on ab initio density functional calculations, we propose $\ensuremath{\gamma}\text{\ensuremath{-}}\mathrm{P}$ and $\ensuremath{\delta}\text{\ensuremath{-}}\mathrm{P}$ as two additional stable structural phases of layered phosphorus besides the $\ensuremath{\alpha}\text{\ensuremath{-}}\mathrm{P}$ (black) $\ensuremath{\beta}\text{\ensuremath{-}}\mathrm{P}$ (blue) allotropes. Monolayers some these allotropes have a wide band gap, whereas others, including...
We demonstrate an aerosol CVD process to dry deposit large-area SWCNT networks with tunable conductivity and optical transmittance on a wide range of substrates including flexible polymers. These can be chemically doped reach sheet resistance as low 110 Ω/⟨ at 90% transmittance. A application potential these is demonstrated by fabricating network-based devices such transparent capacitive touch sensors, thin-film transistors (TFTs), bright organic light-emitting diodes (OLEDs).
Highly stable antimonene, as the cousin of phosphorene from group-VA, has opened up exciting realms in two-dimensional (2D) materials family. However, pristine antimonene is an indirect band gap semiconductor, which greatly restricts its applications for optoelectronics devices. Identifying suitable materials, both responsive to incident photons and efficient carrier transfer, urgently needed ultrathin Herein, by means first-principles computations we found that it rather feasible realize a...
An outstanding challenge of theoretical electronic structure is the description van der Waals (vdW) interactions in molecules and solids. Renewed interest resolving this part motivated by technological promise layered systems including graphite, transition metal dichalcogenides, more recently, black phosphorus, which interlayer interaction widely believed to be dominated these types forces. We report a series quantum Monte Carlo (QMC) calculations for bulk phosphorus related few-layer...
We study the equilibrium geometry and electronic structure of thin films layered gray arsenic using ab initio density functional theory. In contrast to bulk As that is semimetallic, display a significant band gap depends sensitively on number layers, in-layer strain, layer stacking, interlayer spacing. find metallic character can be introduced by increasing layers beyond two or subjecting semiconducting monolayers bilayers moderate tensile strain. The strain-induced metal-semiconductor...
We have developed a magnesia (MgO)-supported iron−copper (FeCu) catalyst to accomplish the growth of single-walled carbon nanotubes (SWNTs) using monoxide (CO) as source at ambient pressure. The FeCu system facilitates small-diameter SWNTs with narrow diameter distribution. UV−vis−NIR optical absorption spectra and photoluminescence excitation (PLE) mapping were used evaluate relative quantities different (n,m) species. also demonstrated that addition Cu Fe can cause remarkable increase in...
Carrier mobility plays a key role in the performance of microelectronic devices, especially field effect transistors (FET). To design next generation two-dimensional (2D) FET, stable channel materials with higher carrier than silicon and significant band gap are highly desirable, but still not discovered. Here, we report group 2D BX (X = P, As, Sb), which semiconducting an ultrahigh mobility. Using first-principles calculations, find that all configurations similar to graphene, possess...
We propose previously unknown allotropes of phosphorus carbide (PC) in the stable shape an atomically thin layer. Different geometries, which result from competition between sp2 bonding found graphitic C and sp3 black P, may be mapped onto 2D tiling patterns that simplify categorizing structures. Depending on category, we identify 2D-PC structures can metallic, semi-metallic with anisotropic Dirac cone, or direct-gap semiconductors their gap tunable by in-layer strain.
In analogy to III-V compounds, which have significantly broadened the scope of group IV semiconductors, we propose IV-VI compounds as isoelectronic counterparts layered V semiconductors. Using {\em ab initio} density functional theory, study yet unrealized structural phases silicon mono-sulfide (SiS). We find black-phosphorus-like $\alpha$-SiS be almost equally stable blue-phosphorus-like $\beta$-SiS. Both and $\beta$-SiS monolayers display a significant, indirect band gap that depends...
A stibarsen [derived from Latin stibium (antimony) and arsenic] or allemontite, is a natural form of arsenic antimonide (SbAs) with the same layered structure as antimony. Thus, exploring two-dimensional SbAs nanosheets great importance to gain insights into properties group V-V compounds at atomic scale. Here, we propose class honeycomb binary compounds, monolayers, which can be tuned semiconductor topological insulator. By ab initio density functional theory, both \ensuremath{\alpha}-SbAs...
We present a scheme to categorize the structure of different layered phosphorene allotropes by mapping their nonplanar atomic onto two-color 2D triangular tiling pattern. In buckled monolayer, we assign atoms in "top" positions dark tiles and "bottom" light tiles. Optimum sp3 bonding is maintained throughout when each tile surrounded same number N like-colored tiles, with 0 ≤ 2. Our ab initio density functional calculations indicate that both relative stability electronic properties depend...
We present a paradigm in constructing very stable, faceted nanotube and fullerene structures by laterally joining nanoribbons or patches of different planar phosphorene phases. Our ab initio density functional calculations indicate that these phases may form nonplanar joints. Unlike fullerenes nanotubes obtained deforming single-phase monolayer at substantial energy penalty, we find to be nearly as stable the monolayers. The resulting rich variety polymorphs allows us tune electronic...
Inspired by successful synthesis of layered SiP single crystals in experiments, we explore their structures, electronic properties, and stability using first-principles calculations. The interlayer interaction crystal is weak, thus mechanical exfoliation viable. We find that undergoes a transition from an indirect band gap to direct 2.59 eV when thinned bulk monolayer. Our calculations also show monolayers are both dynamically thermodynamically stable even at elevated temperatures. Monolayer...
Co–N–GA is synthesized and presents better HER activity in an acidic environment than almost all non-precious metal catalysts.
Ultrathin TeO<sub>2</sub>exhibits a wide direct band-gap and high hole mobility for both power electronics short-wavelength optoelectronic applications.
As a way to further improve the electronic properties of group V layered semiconductors, we propose form in-layer 2D heterostructures black phosphorus and gray arsenic. We use ab initio density functional theory optimize geometry, determine structure, identify most stable allotropes as function composition. Because pure arsenic monolayers differ in their equilibrium predict structural transition change frontier states, including from direct-gap an indirect-gap semiconductor, with changing
Carbon is a girl′s best friend: Carbon-based nanowires have been produced during thermal annealing of diamantane-4,9-dicarboxylic acid in carbon nanotubes under hydrogen atmosphere (see scheme). HR-TEM images, Raman spectra, and structural transformations observed an intense electron beam suggest that the as-produced carbon-based are sp3 diamond nanowires, consistent with our computational results.
Charge transport mechanisms of perovskite-type LaFeO<sub>3</sub> are elucidated for battery-electrode applications.
Group-VA crystals have higher theoretical energy capacities than graphite as anode materials for Li/Na ion batteries. However, their bulks suffer from severe volume expansion and structural breakdown during lithiation or sodiation process, leading to abrupt drop of battery cycle performance. Our experimental computational results reveal that two-dimensional (2D) group-VA can preserve layered configuration without obvious structure damage. Here, we investigate the mechanism 2D P, As, Sb...
A stable three-dimensional layered GaTeCl bulk counterpart is first known from experiment since 1980s.
Nitrogen-doped single-walled carbon nanotubes (N-SWCNTs) were synthesized using a floating catalyst aerosol chemical vapor deposition method, with monoxide as the source, ammonia nitrogen and iron particles derived from evaporated catalyst. The material was deposited on various substrates grown directly gas phase films subsequently characterized by Raman optical absorption spectroscopies, sheet resistance measurements, electron microscopy, energy-loss spectroscopy, X-ray photoelectron...