Query: The chemistry of two-dimensional layered transition metal dichalcogenide nanosheets

Candidate papers:

abstract: Ultrathin two dimensional nanosheets of layered transition metal dichalcogenides (TMDs) are fundamentally and technologically intriguing. In contrast to the graphene sheet, they are chemically versatile. Mono or few layered TMDs obtained either through exfoliation of bulk materials or bottom up syntheses are direct gap semiconductors whose bandgap energy, as well as carrier type (n or p type) varies between compounds depending on their composition, structure and dimensionality. In this Review, we describe how the tunable electronic structure of TMDs makes them attractive for a variety of applications. They have been investigated as chemically active electrocatalysts for hydrogen evolution and hydrosulfurization, as well as electrically active materials in opto electronics. Their morphologies and properties are also useful for energy storage applications such as electrodes for Li ion batteries and supercapacitors.
author_names: Manish Chhowalla

Hyeon Suk Shin

Goki Eda

Lain-Jong Li

Kian Ping Loh

Hua Zhang
title: The chemistry of two dimensional layered transition metal dichalcogenide nanosheets.
venue: Nature chemistry
year: 2013

abstract: Ultrathin two dimensional (2D) nanosheets of layered transition metal dichalcogenides (TMDs) such as MoS2, TiS2, TaS2, WS2, MoSe2, WSe2, etc. are emerging as a class of key materials in chemistry and electronics due to their intriguing chemical and electronic properties. The ability to prepare these TMD nanosheets in high yield and large scale via various methods has led to increasing studies on their hybridization with other materials to create novel functional composites, aiming to engineer their chemical, physical and electronic properties and thus achieve good performance for some specific applications. In this critical review, we will introduce the recent progress in hybrid nanoarchitectures based on 2D TMD nanosheets. Their synthetic strategies, properties and applications are systematically summarized and discussed, with emphasis on those new appealing structures, properties and functions. In addition, we will also give some perspectives on the challenges and opportunities in this promising research area.
author_names: Chaoliang Tan

Hua Zhang
title: Two dimensional transition metal dichalcogenide nanosheet based composites.
venue: Chemical Society reviews
year: 2015

abstract: Group 6 transition metal dichalcogenides (G6 TMDs) most notably MoS2, MoSe2, MoTe2, WS2 and WSe2, constitute an important class of materials with a layered crystal structure. Various types of G6 TMD nanomaterials, such as nanosheets, nanotubes and quantum dot nano objects and flower like nanostructures, have been synthesized. High thermodynamic stability under ambient conditions, even in atomically thin form, made nanosheets of these inorganic semiconductors a valuable asset in the existing library of two dimensional (2D) materials, along with the well known semimetallic graphene and insulating hexagonal boron nitride. G6 TMDs generally possess an appropriate bandgap (1 2 eV) which is tunable by size and dimensionality and changes from indirect to direct in monolayer nanosheets, intriguing for (opto)electronic, sensing, and solar energy harvesting applications. Moreover, rich intercalation chemistry and abundance of catalytically active edge sites make them promising for fabrication of novel energy storage devices and advanced catalysts. In this review, we provide an overview on all aspects of the basic science, physicochemical properties and characterization techniques as well as all existing production methods and applications of G6 TMD nanomaterials in a comprehensive yet concise treatment. Particular emphasis is placed on establishing a linkage between the features of production methods and the specific needs of rapidly growing applications of G6 TMDs to develop a production application selection guide. Based on this selection guide, a framework is suggested for future research on how to bridge existing knowledge gaps and improve current production methods towards technological application of G6 TMD nanomaterials.
author_names: Morasae Samadi

N Sarikhani

Mohammad Zirak

Hua Zhang

Alireza Z Moshfegh
title: Group 6 transition metal dichalcogenide nanomaterials: synthesis, applications and future perspectives.
venue: Nanoscale horizons
year: 2018

abstract: Semimetallic layered transition metal dichalcogenides, such as TiS2, can serve as a platform material for exploring novel physics modulated by dimensionality, as well as for developing versatile applications in electronics and thermoelectrics. However, controlled synthesis of ultrathin TiS2 in a dry chemistry way has yet to be realized because of the high oxophilicity of active Ti precursors. Here, we report the ambient pressure chemical vapor deposition (CVD) method to grow large size, highly crystalline two dimensional (2D) TiS2 nanosheets through in situ generating titanium chloride as the gaseous precursor. The addition of NH4Cl promoter can react with Ti powders and switch the solid phase sulfurization reaction into a CVD process, thus enabling the controllability over the size, shape, and thickness of the TiS2 nanosheets via tuning the synthesis conditions. Interestingly, this semimetallic 2D material exhibits near infrared surface plasmon resonance absorption and a memristor like electrical behavior, both holding promise for further application developments. Our method hence opens a new avenue for the CVD growth of 2D metal dichalcogenides directly from metal powders and pave the way for exploring their intriguing properties and applications.
author_names: Zhenfei Gao

Qingqing Ji

Pin-Chun Shen

Yimo Han

Wei Sun Leong

Nannan Mao

Lin Zhou

Cong Su

Jingjing Niu

Xiang Ji

Mahomed Mehdi Goulamaly

David A Muller

Yongfeng Li

Jing Kong
title: In Situ Generated Volatile Precursor for CVD Growth of a Semimetallic 2D Dichalcogenide.
venue: ACS applied materials interfaces
year: 2018

abstract: In this report, we will provide a comprehensive introduction to the investigations on the combination of elemental junction and planar heterostructure in TMDCs in terms of preparation and characterization mechanisms.
author_names: Kun Chen

Li Tao

Xi Wan

Jianbin Xu
title: Preparation and Characterization of Two Dimensional Layered Transition Metal Dichalcogenide Thin Films
year: 2019

abstract: Transition metal dichalcogenide (TMD) monolayers and heterostructures have emerged as a compelling class of materials with transformative properties that may be harnessed for novel device technolog.
author_names: Tanushree H Choudhury

Xiaotian Zhang

Zakaria Y Al Balushi

Mikhail Chubarov

Joan M Redwing
title: Epitaxial Growth of Two Dimensional Layered Transition Metal Dichalcogenides
year: 2020

abstract: MoS2, MoSe2 and WSe2 thin flakes were fabricated by the standard micromechanical cleavage procedures. The thickness and the optical contrast of the atomic thin dichalcogenide flakes on SiO2/Si substrates were measured by atomic force microscopy (AFM) and spectroscopic ellipsometer. A rapid and nondestructive method by using reflection spectra was proposed to identify the layer number of 2D layered transition metal dichalcogenides on SiO2 (275 nm)/Si substrates. The contrast spectra of 2D nanosheets with different layer numbers are in agreement with theoretical calculations based on Fresnel's law, indicating that this method provides an unambiguous and nondestructive contrast spectra fingerprint for identifying single and few layered transition metal dichalcogenides. The results will greatly help in fundamental research and application.
author_names: Jia-Peng Wu

Le Wang

Li-Yuan Zhang
title: Rapid and nondestructive layer number identification of two dimensional layered transition metal dichalcogenides
venue: Rare Metals
year: 2017

abstract: This special issue is about two dimensional transition metal dichalcogenides (2D TMDs) a family of materials consisting of over 40 compounds with the generalized formula of MX2, where M is a transition metal typically from groups 4 7, and X is a chalcogen such as S, Se or Te. Bulk TMDs have been widely studied over several decades because it is possible to formulate compounds with disparate electronic structures. In the bulk form, MX2 compounds are layered materials (or van der Waals solids) in which there is strong intralayer bonding and weak interlayer bonding. Each individual layer of the TMDs consists of three atomic layers in which the transition metal is sandwiched by two chalcogens. Furthermore, the chalcogen atoms are saturated and therefore are not highly reactive. These features allow for the attainment of individual layers of the TMDs by several exfoliation or vapor deposition methods. The isolation of monolayers of TMDs leads to the dramatic changes in their properties, primarily due to the confinement of charge carriers in two dimensions (xand y directions) due to the absence of interactions in the z direction. Thus, singlelayered nanosheets are two dimensional materials that possess dramatically different a Materials Science and Engineering, Rutgers University, 607 Taylor Road, Piscataway, NJ 08854, USA. E mail: manish1@rci.rutgers.edu b Center for Nanochemistry (CNC) Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, People's Republic of China. E mail: zfliu@pku.edu.cn c School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore. E mail: hzhang@ntu.edu.sg
author_names: Manish Chhowalla

Zhongfan Liu

Hua Zhang
title: Two dimensional transition metal dichalcogenide (TMD) nanosheets.
venue: Chemical Society reviews
year: 2015

abstract: Recently there have been many research breakthroughs in two dimensional (2D) materials including graphene, boron nitride (h BN) black phosphors (BPs) and transition metal dichalcogenides (TMDCs) The unique electrical, optical, and thermal properties in 2D materials are associated with their strictly defined low dimensionalities. These materials provide a wide range of basic building blocks for next generation electronics. The chemical vapor deposition (CVD) technique has shown great promise to generate high quality TMDC layers with scalable size, controllable thickness, and excellent electronic properties suitable for both technological applications and fundamental sciences. The capability to precisely engineer 2D materials by chemical approaches has also given rise to fascinating new physics, which could lead to exciting new applications. In this Review, we introduce the latest development of TMDC synthesis by CVD approaches and provide further insight for the controllable and reliable synthesis of atomically thin TMDCs. Understanding of the vapor phase growth mechanism of 2D TMDCs could benefit the formation of complicated heterostructures and novel artificial 2D lattices.
author_names: Henan Li

Ying Li

Areej Aljarb

Yumeng Shi

Lain-Jong Li
title: Epitaxial Growth of Two Dimensional Layered Transition Metal Dichalcogenides: Growth Mechanism, Controllability, and Scalability.
venue: Chemical reviews
year: 2018

abstract: Owing to an ultrathin body, atomic scale smoothness, dangling bond free surface, and sizable bandgap, transistors based on two dimensional (2D) layered semiconductors show the potential of scalability down to the nanoscale, high density three dimensional integration, and superior performance in terms of better electrostatic control and smaller power consumption compared with conventional three dimensional semiconductors (Si, Ge, and III V compound materials) To apply 2D layered materials into complementary metal oxide semiconductor logic circuits, it is important to modulate the carrier type and density in a controllable manner, and engineer the contact (between metal electrode and 2D semiconductor) and the interface (between dielectrics and semiconducting channel) to get close to their intrinsic carrier mobility. In this review, the most widely studied 2D transition metal dichalcogenides (TMD) are focused on, and an overview of recent progress on doping, contact, and interface engineering of the TMD based field effect transistors is provided.
author_names: Yuda Zhao

Kang Xu

Feng Pan

Changjian Zhou

Feichi Zhou

Yang Chai
title: Doping, Contact and Interface Engineering of Two Dimensional Layered Transition Metal Dichalcogenides Transistors
year: 2017