151
|
Limbu TB, Adhikari B, Song SK, Chitara B, Tang Y, Parsons GN, Yan F. Toward understanding the phase-selective growth mechanism of films and geometrically-shaped flakes of 2D MoTe 2. RSC Adv 2021; 11:38839-38848. [PMID: 35493247 PMCID: PMC9044229 DOI: 10.1039/d1ra07787b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 11/30/2021] [Indexed: 12/21/2022] Open
Abstract
Two-dimensional (2D) molybdenum ditelluride (MoTe2) is an interesting material for fundamental study and applications, due to its ability to exist in different polymorphs of 2H, 1T, and 1T′, their phase change behavior, and unique electronic properties. Although much progress has been made in the growth of high-quality flakes and films of 2H and 1T′-MoTe2 phases, phase-selective growth of all three phases remains a huge challenge, due to the lack of enough information on their growth mechanism. Herein, we present a novel approach to growing films and geometrical-shaped few-layer flakes of 2D 2H-, 1T-, and 1T′-MoTe2 by atmospheric-pressure chemical vapor deposition (APCVD) and present a thorough understanding of the phase-selective growth mechanism by employing the concept of thermodynamics and chemical kinetics involved in the growth processes. Our approach involves optimization of growth parameters and understanding using thermodynamical software, HSC Chemistry. A lattice strain-mediated mechanism has been proposed to explain the phase selective growth of 2D MoTe2, and different chemical kinetics-guided strategies have been developed to grow MoTe2 flakes and films. This study investigates the phase-controlled growth of flakes and films of 2D MoTe2 by atmospheric-pressure chemical vapor deposition and presents a thorough understanding on the growth mechanism.![]()
Collapse
Affiliation(s)
- Tej B Limbu
- Department of Chemistry and Biochemistry, North Carolina Central University Durham NC 27707 USA .,Department of Physical and Applied Sciences, University of Houston-Clear Lake Houston TX 77058 USA
| | - Bikram Adhikari
- Department of Chemistry and Biochemistry, North Carolina Central University Durham NC 27707 USA
| | - Seung Keun Song
- Department of Chemical and Biomolecular Engineering, North Carolina State University Raleigh North Carolina 27695 USA
| | - Basant Chitara
- Department of Chemistry and Biochemistry, North Carolina Central University Durham NC 27707 USA
| | - Yongan Tang
- Department of Mathematics and Physics, North Carolina Central University Durham NC 27707 USA
| | - Gregory N Parsons
- Department of Chemical and Biomolecular Engineering, North Carolina State University Raleigh North Carolina 27695 USA
| | - Fei Yan
- Department of Chemistry and Biochemistry, North Carolina Central University Durham NC 27707 USA
| |
Collapse
|
152
|
Ni J, Fu Q, Ostrikov KK, Gu X, Nan H, Xiao S. Status and prospects of Ohmic contacts on two-dimensional semiconductors. NANOTECHNOLOGY 2021; 33:062005. [PMID: 34649226 DOI: 10.1088/1361-6528/ac2fe1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Accepted: 10/14/2021] [Indexed: 06/13/2023]
Abstract
In recent years, two-dimensional materials have received more and more attention in the development of semiconductor devices, and their practical applications in optoelectronic devices have also developed rapidly. However, there are still some factors that limit the performance of two-dimensional semiconductor material devices, and one of the most important is Ohmic contact. Here, we elaborate on a variety of approaches to achieve Ohmic contacts on two-dimensional materials and reveal their physical mechanisms. For the work function mismatch problem, we summarize the comparison of barrier heights between different metals and 2D semiconductors. We also examine different methods to solve the problem of Fermi level pinning. For the novel 2D metal-semiconductor contact methods, we analyse their effects on reducing contact resistance from two different perspectives: homojunction and heterojunction. Finally, the challenges of 2D semiconductors in achieving Ohmic contacts are outlined.
Collapse
Affiliation(s)
- Junhao Ni
- Engineering Research Center of IoT Technology Applications (Ministry of Education), Department of Electronic Engineering, Jiangnan University, Wuxi 214122, People's Republic of China
| | - Quangui Fu
- Engineering Research Center of IoT Technology Applications (Ministry of Education), Department of Electronic Engineering, Jiangnan University, Wuxi 214122, People's Republic of China
| | - Kostya Ken Ostrikov
- School of Chemistry and Physics and QUT Centre for Materials Science, Queensland University of Technology (QUT), Brisbane QLD 4000, Australia
| | - Xiaofeng Gu
- Engineering Research Center of IoT Technology Applications (Ministry of Education), Department of Electronic Engineering, Jiangnan University, Wuxi 214122, People's Republic of China
| | - Haiyan Nan
- Engineering Research Center of IoT Technology Applications (Ministry of Education), Department of Electronic Engineering, Jiangnan University, Wuxi 214122, People's Republic of China
| | - Shaoqing Xiao
- Engineering Research Center of IoT Technology Applications (Ministry of Education), Department of Electronic Engineering, Jiangnan University, Wuxi 214122, People's Republic of China
| |
Collapse
|
153
|
MoTe 2 Field-Effect Transistors with Low Contact Resistance through Phase Tuning by Laser Irradiation. NANOMATERIALS 2021; 11:nano11112805. [PMID: 34835570 PMCID: PMC8620056 DOI: 10.3390/nano11112805] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 10/18/2021] [Accepted: 10/20/2021] [Indexed: 11/17/2022]
Abstract
Due to their extraordinary electrical and physical properties, two-dimensional (2D) transition metal dichalcogenides (TMDs) are considered promising for use in next-generation electrical devices. However, the application of TMD-based devices is limited because of the Schottky barrier interface resulting from the absence of dangling bonds on the TMDs’ surface. Here, we introduce a facile phase-tuning approach for forming a homogenous interface between semiconducting hexagonal (2H) and semi-metallic monoclinic (1T′) molybdenum ditelluride (MoTe2). The formation of ohmic contacts increases the charge carrier mobility of MoTe2 field-effect transistor devices to 16.1 cm2 V−1s−1 with high reproducibility, while maintaining a high on/off current ratio by efficiently improving charge injection at the interface. The proposed method enables a simple fabrication process, local patterning, and large-area scaling for the creation of high-performance 2D electronic devices.
Collapse
|
154
|
Hernandez Ruiz K, Wang Z, Ciprian M, Zhu M, Tu R, Zhang L, Luo W, Fan Y, Jiang W. Chemical Vapor Deposition Mediated Phase Engineering for 2D Transition Metal Dichalcogenides: Strategies and Applications. SMALL SCIENCE 2021. [DOI: 10.1002/smsc.202100047] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Karla Hernandez Ruiz
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials Institute of Functional Materials College of Materials Science and Engineering, Donghua University Shanghai 201620 China
| | - Ziqian Wang
- Department of Materials Science and Engineering Johns Hopkins University Baltimore MD 21218 USA
| | - Matteo Ciprian
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials Institute of Functional Materials College of Materials Science and Engineering, Donghua University Shanghai 201620 China
| | - Meifang Zhu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials Institute of Functional Materials College of Materials Science and Engineering, Donghua University Shanghai 201620 China
| | - Rong Tu
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070 China
| | - Lianmeng Zhang
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070 China
| | - Wei Luo
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials Institute of Functional Materials College of Materials Science and Engineering, Donghua University Shanghai 201620 China
| | - Yuchi Fan
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials Institute of Functional Materials College of Materials Science and Engineering, Donghua University Shanghai 201620 China
| | - Wan Jiang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials Institute of Functional Materials College of Materials Science and Engineering, Donghua University Shanghai 201620 China
| |
Collapse
|
155
|
Pathan MAK, Gupta A, Vaida ME. Exploring the growth and oxidation of 2D-TaS 2on Cu(111). NANOTECHNOLOGY 2021; 32:505605. [PMID: 34492643 DOI: 10.1088/1361-6528/ac244e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 09/07/2021] [Indexed: 06/13/2023]
Abstract
In this work, the growth and stability towards O2exposure of two dimensional (2D) TaS2on a Cu(111) substrate is investigated. Large area (∼1 cm2) crystalline 2D-TaS2films with a metallic character are prepared on a single crystal Cu(111) substrate via a multistep approach based on physical vapor deposition. Analytical techniques such as Auger electron spectroscopy, low energy electron diffraction, and photoemission spectroscopy are used to characterize the composition, crystallinity, and electronic structure of the surface. At coverages below one monolayer equivalent (ML), misoriented TaS2domains are formed, which are rotated up to±13orelative to the Cu(111) crystallographic directions. The TaS2domains misorientation decreases as the film thickness approaches 1 ML, at which the crystallographic directions of TaS2and Cu(111) are aligned. The TaS2film is found to grow epitaxially on Cu(111). As revealed by low energy electron diffraction in conjunction with an atomic model simulation, the (3 × 3) unit cells of TaS2match the (4 × 4) supercell of Cu(111). Furthermore, the exposure of TaS2to O2, does not lead to the formation of a robust tantalum oxide film, only minor amounts of stable oxides being detected on the surface. Instead, the exposure of TaS2films to O2leads predominantly to a reduction of the film thickness, evidenced by a decrease in the content of both Ta and S atoms of the film. This is attributed to the formation of oxide species that are unstable and mainly desorb from the surface below room temperature. Temperature programmed desorption spectroscopy confirms the formation of SO2, which desorbs from the surface between 100 and500 K.These results provide new insights into the oxidative degradation of 2D-TaS2on Cu(111).
Collapse
Affiliation(s)
- Md Afjal Khan Pathan
- Department of Physics, University of Central Florida, Orlando, FL 32816, United States of America
| | - Aakash Gupta
- Department of Physics, University of Central Florida, Orlando, FL 32816, United States of America
| | - Mihai E Vaida
- Department of Physics, University of Central Florida, Orlando, FL 32816, United States of America
- Renewable Energy and Chemical Transformation Cluster, University of Central Florida, Orlando, FL 32816, United States of America
| |
Collapse
|
156
|
Li F, Chen M, Wang Y, Zhu X, Zhang X, Zou Z, Zhang D, Yi J, Li Z, Li D, Pan A. Strain-controlled synthesis of ultrathin hexagonal GaTe/MoS 2 heterostructure for sensitive photodetection. iScience 2021; 24:103031. [PMID: 34541467 PMCID: PMC8437799 DOI: 10.1016/j.isci.2021.103031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 06/15/2021] [Accepted: 08/20/2021] [Indexed: 11/18/2022] Open
Abstract
Ultrathin hexagonal GaTe, with relatively high charge density, holds great potential in the field of optoelectronic devices. However, the thermodynamical stability limits it fabrications as well as applications. Here, by introducing two-dimensional MoS2 as the substrate, we successfully realized the phase-controlled synthesis of ultrathin h-GaTe, leading to high-quality h-GaTe/MoS2 heterostructures. Theoretical calculation studies reveal that GaTe with hexagonal phase is more thermodynamically stable on MoS2 templates, which can be attributed to the strain stretching and the formation energy reduction. Based on the achieved p-n heterostructures, optoelectronic devices are designed and probed, where remarkable photoresponsivity (32.5 A/W) and fast photoresponse speed (<50 μs) are obtained, indicating well-behaved photo-sensing behaviors. The study here could offer a good reference for the controlled growth of the relevant materials, and the achieved heterostructure will find promising applications in future integrated electronic and optoelectronic devices and systems.
Collapse
Affiliation(s)
- Fang Li
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, College of Materials Science and Engineering, School of Physics and Electronics, Hunan University, Changsha, Hunan 410082, China
- Key Laboratory of Inferior Crude Oil Processing of Guangdong Provincial Higher Education Institutes, School of Chemical Engineering, Guangdong University of Petrochemical Technology, Maoming, Guangdong 525000, China
| | - Mingxing Chen
- Key Laboratory for Matter Microstructure and Function of Hunan Province, Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education, School of Physics and Electronics, Hunan Normal University, Changsha 410081, China
| | - Yajuan Wang
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, College of Materials Science and Engineering, School of Physics and Electronics, Hunan University, Changsha, Hunan 410082, China
| | - Xiaoli Zhu
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, College of Materials Science and Engineering, School of Physics and Electronics, Hunan University, Changsha, Hunan 410082, China
| | - Xuehong Zhang
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, College of Materials Science and Engineering, School of Physics and Electronics, Hunan University, Changsha, Hunan 410082, China
| | - Zixing Zou
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, College of Materials Science and Engineering, School of Physics and Electronics, Hunan University, Changsha, Hunan 410082, China
| | - Danliang Zhang
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, College of Materials Science and Engineering, School of Physics and Electronics, Hunan University, Changsha, Hunan 410082, China
| | - Jiali Yi
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, College of Materials Science and Engineering, School of Physics and Electronics, Hunan University, Changsha, Hunan 410082, China
| | - Ziwei Li
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, College of Materials Science and Engineering, School of Physics and Electronics, Hunan University, Changsha, Hunan 410082, China
| | - Dong Li
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, College of Materials Science and Engineering, School of Physics and Electronics, Hunan University, Changsha, Hunan 410082, China
| | - Anlian Pan
- Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, College of Materials Science and Engineering, School of Physics and Electronics, Hunan University, Changsha, Hunan 410082, China
| |
Collapse
|
157
|
Han X, Liang X, He D, Jiao L, Wang Y, Zhao H. Photocarrier Dynamics in MoTe 2 Nanofilms with 2 H and Distorted 1 T Lattice Structures. ACS APPLIED MATERIALS & INTERFACES 2021; 13:44703-44710. [PMID: 34494811 DOI: 10.1021/acsami.1c09698] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Molybdenum telluride (MoTe2), an emerging layered two-dimensional (2D) material, possesses excellent phase-changing properties. Previous studies revealed its reversible transition between 2H and 1T' phases with a transition energy as small as 35 meV. Since 1T'-MoTe2 is metallic, it can serve as an electrical contact for semiconducting 2H-MoTe2-based optoelectronic devices. Here, the photocarrier dynamics in MoTe2 nanofilms synthesized by a one-step method and with coexisting multiple phases are investigated by transient absorption measurements. Both the energy relaxation time and the recombination lifetime of the excitons are shorter in the 1T'-MoTe2 compared to its 2H phase. These results provide information on the different photocarrier dynamical properties of these two phases, which is important for future 2D optoelectronic and phase-change electronic devices based on MoTe2.
Collapse
Affiliation(s)
- Xiuxiu Han
- Key Laboratory of Luminescence and Optical Information, Ministry of Education, Institute of Optoelectronic Technology, Beijing Jiaotong University, Beijing 100044, China
| | - Xingyao Liang
- Key Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education, Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Dawei He
- Key Laboratory of Luminescence and Optical Information, Ministry of Education, Institute of Optoelectronic Technology, Beijing Jiaotong University, Beijing 100044, China
| | - Liying Jiao
- Key Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education, Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Yongsheng Wang
- Key Laboratory of Luminescence and Optical Information, Ministry of Education, Institute of Optoelectronic Technology, Beijing Jiaotong University, Beijing 100044, China
| | - Hui Zhao
- Department of Physics and Astronomy, The University of Kansas, Lawrence, Kansas 66045, United States
| |
Collapse
|
158
|
Bie YQ, Zong A, Wang X, Jarillo-Herrero P, Gedik N. A versatile sample fabrication method for ultrafast electron diffraction. Ultramicroscopy 2021; 230:113389. [PMID: 34530284 DOI: 10.1016/j.ultramic.2021.113389] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 08/21/2021] [Accepted: 08/30/2021] [Indexed: 11/16/2022]
Abstract
Integral to the exploration of nonequilibrium phenomena in solid-state systems is the study of lattice motion after photoexcitation by a femtosecond laser pulse. For the past two decades, ultrafast electron diffraction (UED) has played a critical role in this regard. Despite remarkable progress in instrumental development, this technique is still bottlenecked by a demanding sample preparation process, where ultrathin single crystals of large lateral size are typically required. In this work, we describe an efficient, versatile method that yields high-quality, laterally extended (≥ 100 µm), and thin (≤ 50 nm) single crystals on amorphous films of Si3N4 windows. It applies to most exfoliable materials, including those reactive in ambient conditions, and promises clean, flat surfaces. Besides the natural extension to fabricating van der Waals heterostructures, our method can also be applied to future-generation UED that enables additional control of sample parameters, such as electrostatic gating and excitation by a locally enhanced terahertz field. Our work significantly expands the type of samples for UED studies and also finds application in other time-resolved techniques such as attosecond extreme-ultraviolet absorption spectroscopy. This method hence provides further opportunities to explore photoinduced transitions and to discover novel states of matter out of equilibrium.
Collapse
Affiliation(s)
- Ya-Qing Bie
- State Key Lab of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou, 510275, China; Massachusetts Institute of Technology, Department of Physics, Cambridge, MA 02139, United States
| | - Alfred Zong
- Massachusetts Institute of Technology, Department of Physics, Cambridge, MA 02139, United States; University of California at Berkeley, Department of Chemistry, Berkeley, CA 94720, United States
| | - Xirui Wang
- Massachusetts Institute of Technology, Department of Physics, Cambridge, MA 02139, United States
| | - Pablo Jarillo-Herrero
- Massachusetts Institute of Technology, Department of Physics, Cambridge, MA 02139, United States
| | - Nuh Gedik
- Massachusetts Institute of Technology, Department of Physics, Cambridge, MA 02139, United States.
| |
Collapse
|
159
|
Kang G, Hong D, Kim JY, Lee GD, Lee S, Nam DH, Joo YC. Phase Engineering of Transition Metal Dichalcogenides via a Thermodynamically Designed Gas-Solid Reaction. J Phys Chem Lett 2021; 12:8430-8439. [PMID: 34436917 DOI: 10.1021/acs.jpclett.1c02476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Polymorph conversion of transition metal dichalcogenides (TMDs) offers intriguing material phenomena that can be applied for tuning the intrinsic properties of 2D materials. In general, group VIB TMDs can have thermodynamically stable 2H phases and metastable 1T/T' phases. Herein, we report key principles to apply carbon monoxide (CO)-based gas-solid reactions for a universal polymorph conversion of group VIB TMDs without forming undesirable compounds. We found that the process conditions are strongly dependent on the reaction chemical potential of cations in the TMDs, which can be predicted by thermodynamic calculations, and that polymorphic conversion is triggered by S vacancy (VS) formation. Furthermore, we conducted DFT calculations for the reaction barriers of VS formation and S diffusion to reveal the polymorph conversion mechanism of WS2 and compared it with that of MoS2. We believe that phase engineering 2D materials via thermodynamically designed gas-solid reactions could be functionally used to achieve defect-related nanomaterials.
Collapse
Affiliation(s)
- Geosan Kang
- Department of Materials Science & Engineering, Seoul National University, Seoul 08826, Republic of Korea
| | - Deokgi Hong
- Department of Materials Science & Engineering, Seoul National University, Seoul 08826, Republic of Korea
| | - Ji-Yong Kim
- Department of Materials Science & Engineering, Seoul National University, Seoul 08826, Republic of Korea
| | - Gun-Do Lee
- Department of Materials Science & Engineering, Seoul National University, Seoul 08826, Republic of Korea
- Research Institute of Advanced Materials (RIAM), Seoul National University, Seoul 08826, Republic of Korea
| | - Sungwoo Lee
- Department of Materials Science & Engineering, Seoul National University, Seoul 08826, Republic of Korea
- Research Institute of Advanced Materials (RIAM), Seoul National University, Seoul 08826, Republic of Korea
| | - Dae-Hyun Nam
- Department of Energy Science & Engineering, Daegu Gyeongbuk Institute of Science & Technology (DGIST), Daegu 42988, Republic of Korea
| | - Young-Chang Joo
- Department of Materials Science & Engineering, Seoul National University, Seoul 08826, Republic of Korea
- Research Institute of Advanced Materials (RIAM), Seoul National University, Seoul 08826, Republic of Korea
- Advanced Institute of Convergence Technology, 145 Gwanggyo-ro, Yeongtong-gu, Suwon 16229, Republic of Korea
| |
Collapse
|
160
|
Deng Y, Zhao X, Zhu C, Li P, Duan R, Liu G, Liu Z. MoTe 2: Semiconductor or Semimetal? ACS NANO 2021; 15:12465-12474. [PMID: 34379388 DOI: 10.1021/acsnano.1c01816] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Transition metal tellurides (TMTs) have attracted intense interest due to their intriguing physical properties arising from their diverse phase topologies. To date, a wide range of physical properties have been discovered for TMTs, including that they can act as topological insulators, semiconductors, Weyl semimetals, and superconductors. Among the TMT families, MoTe2 is a representative material because of its Janus nature and rich phases. In this Perspective, we first introduce phase structures in monolayer and bulk MoTe2 and then summarize MoTe2 synthesis strategies. We highlight recent advances of Janus MoTe2 in terms of material structures and emerging quantum states. We also provide insight into the opportunities and challenges faced by MoTe2-associated device design and applications.
Collapse
Affiliation(s)
- Ya Deng
- School of Materials Science and Engineering, Nanyang Technological University, 639798 Singapore
| | - Xiaoxu Zhao
- School of Materials Science and Engineering, Nanyang Technological University, 639798 Singapore
| | - Chao Zhu
- School of Materials Science and Engineering, Nanyang Technological University, 639798 Singapore
| | - Peiling Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Ruihuan Duan
- School of Materials Science and Engineering, Nanyang Technological University, 639798 Singapore
| | - Guangtong Liu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Zheng Liu
- School of Materials Science and Engineering, Nanyang Technological University, 639798 Singapore
- School of Electrical and Electronic Engineering, Nanyang Technological University, 639798 Singapore
- CINTRA CNRS/NTU/THALES, UMI 3288, 637553 Singapore
| |
Collapse
|
161
|
Ghimire G, Dhakal KP, Choi W, Esthete YA, Kim SJ, Tran TT, Lee H, Yang H, Duong DL, Kim YM, Kim J. Doping-Mediated Lattice Engineering of Monolayer ReS 2 for Modulating In-Plane Anisotropy of Optical and Transport Properties. ACS NANO 2021; 15:13770-13780. [PMID: 34296605 DOI: 10.1021/acsnano.1c05316] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
ReS2 exhibits strong anisotropic optical and electrical responses originating from the asymmetric lattice. Here, we show that the anisotropy of monolayer (1L) ReS2 in optical scattering and electrical transport can be practically erased by lattice engineering via lithium (Li) treatment. Scanning transmission electron microscopy revealed that significant strain is induced in the lattice of Li-treated 1L-ReS2, due to high-density electron doping and the resultant formation of continuous tiling of nanodomains with randomly rotating orientations of 60°, which produced a nearly isotropic response of polarized Raman scattering and absorption of Li-treated 1L-ReS2. With Li treatment, the in-plane conductance of 1L-ReS2 increased by an order of magnitude, and its angle dependence became negligible. Our result that the asymmetric phase was converted into the isotropic phase by electron injection could significantly expand the optoelectronic applications of polymorphic two-dimensional transition metal dichalcogenides.
Collapse
Affiliation(s)
- Ganesh Ghimire
- Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Krishna P Dhakal
- Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Wooseon Choi
- Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Yonas Assefa Esthete
- Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Seon Je Kim
- Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Trang Thu Tran
- Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Hyoyoung Lee
- Center for Integrated Nanostructure Physics, Institute for Basic Science, Suwon 16419, Republic of Korea
- Department of Chemistry, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Heejun Yang
- Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
- Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Dinh Loc Duong
- Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
- Center for Integrated Nanostructure Physics, Institute for Basic Science, Suwon 16419, Republic of Korea
| | - Young-Min Kim
- Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
- Center for Integrated Nanostructure Physics, Institute for Basic Science, Suwon 16419, Republic of Korea
| | - Jeongyong Kim
- Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea
| |
Collapse
|
162
|
Ma L, Zhu J, Li W, Huang R, Wang X, Guo J, Choi JH, Lou Y, Wang D, Zou G. Immobilized Precursor Particle Driven Growth of Centimeter-Sized MoTe 2 Monolayer. J Am Chem Soc 2021; 143:13314-13324. [PMID: 34375083 DOI: 10.1021/jacs.1c06250] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Molybdenum ditelluride (MoTe2) has attracted ever-growing attention in recent years due to its novel characteristics in spintronics and phase-engineering, and an efficient and convenient method to achieve large-area high-quality film is an essential step toward electronic applications. However, the growth of large-area monolayer MoTe2 is challenging. Here, for the first time, we achieve the growth of a centimeter-sized monoclinic MoTe2 monolayer and manifest the mechanism of immobilized precursor particle driven growth. Microscopic characterizations reveal an obvious trend of immobilized precursor particles being consumed by the monolayer and continuing to provide a source for the growth of the monolayer. Time-of-flight secondary ion mass spectrometry verifies the attachment of hydroxide ions on the surface of the MoTe2 monolayer, thereby realizing the inhibition of crystal growth along the [001] zone axis and the continuous growth of the MoTe2 monolayer. The first-principles DFT calculations prove the mechanism of immobilized precursor particles and the absorption of hydroxide ions on the MoTe2 monolayer. The as-grown MoTe2 monolayer exhibits a surface roughness of 0.19 nm and average conductivity of 1.5 × 10-5 S/m, which prove the smoothness and uniformity of the MoTe2 monolayer. Temperature-dependent electrical measurements together with the transfer characteristic curves further demonstrate the typical semimetallic properties of monoclinic MoTe2. Our research elaborates the microscopic process of immobilized precursor particles to grow large-area MoTe2 monolayer and provides a new thinking about the growth of many other two-dimensional materials.
Collapse
Affiliation(s)
- Liang Ma
- College of Energy, Soochow Institute for Energy and Materials Innovations, and Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou 215123 China
| | - Juntong Zhu
- College of Energy, Soochow Institute for Energy and Materials Innovations, and Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou 215123 China
| | - Wei Li
- College of Energy, Soochow Institute for Energy and Materials Innovations, and Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou 215123 China
| | - Rong Huang
- Vacuum Interconnected Nanotech Workstation, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (CAS), Suzhou 215123 China
| | - Xiangyi Wang
- College of Energy, Soochow Institute for Energy and Materials Innovations, and Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou 215123 China
| | - Jun Guo
- Testing and Analysis Center, Soochow University, Suzhou 215123, China
| | - Jin-Ho Choi
- College of Energy, Soochow Institute for Energy and Materials Innovations, and Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou 215123 China
| | - Yanhui Lou
- College of Energy, Soochow Institute for Energy and Materials Innovations, and Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou 215123 China
| | - Dan Wang
- College of Energy, Soochow Institute for Energy and Materials Innovations, and Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou 215123 China
| | - Guifu Zou
- College of Energy, Soochow Institute for Energy and Materials Innovations, and Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou 215123 China
| |
Collapse
|
163
|
Wu H, Yu X, Zhu M, Zhu Z, Zhang J, Zhang S, Qin S, Wang G, Peng G, Dai J, Novoselov KS. Direct Visualization and Manipulation of Stacking Orders in Few-Layer Graphene by Dynamic Atomic Force Microscopy. J Phys Chem Lett 2021; 12:7328-7334. [PMID: 34319748 DOI: 10.1021/acs.jpclett.1c01579] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Stacking order plays a central role in governing a wide range of properties in layered two-dimensional materials. In the case of few-layer graphene, there are two common stacking configurations: ABA and ABC stacking, which have been proven to exhibit dramatically different electronic properties. However, the controllable characterization and manipulation between them remain a great challenge. Here, we report that ABA- and ABC-stacked domains can be directly visualized in phase imaging by tapping-mode atomic force microscopy with much higher spatial resolution than conventional optical spectroscopy. The contrasting phase is caused by the different energy dissipation by the tip-sample interaction. We further demonstrate controllable manipulation on the ABA/ABC domain walls by means of propagating stress transverse waves generated by the tapping of tip. Our results offer a reliable strategy for direct imaging and precise control of the atomic structures in few-layer graphene, which can be extended to other two-dimensional materials.
Collapse
Affiliation(s)
- Hongjian Wu
- Department of Physics, National University of Defense Technology, Changsha 410073, Hunan, China
| | - Xiaoxiang Yu
- Department of Physics, National University of Defense Technology, Changsha 410073, Hunan, China
| | - Mengjian Zhu
- College of Advanced Interdisciplinary Studies & Hunan Provincial Key Laboratory of Novel Nano-Optoelectronic Information Materials and Devices, National University of Defense Technology, Changsha 410073, Hunan, China
| | - Zhihong Zhu
- College of Advanced Interdisciplinary Studies & Hunan Provincial Key Laboratory of Novel Nano-Optoelectronic Information Materials and Devices, National University of Defense Technology, Changsha 410073, Hunan, China
| | - Jianyu Zhang
- Institute of Electronic Engineering, China Academy of Engineering Physics, Mianyang 621900, Sichuan, China
| | - Sen Zhang
- Department of Physics, National University of Defense Technology, Changsha 410073, Hunan, China
| | - Shiqiao Qin
- College of Advanced Interdisciplinary Studies & Hunan Provincial Key Laboratory of Novel Nano-Optoelectronic Information Materials and Devices, National University of Defense Technology, Changsha 410073, Hunan, China
| | - Guang Wang
- Department of Physics, National University of Defense Technology, Changsha 410073, Hunan, China
| | - Gang Peng
- Department of Physics, National University of Defense Technology, Changsha 410073, Hunan, China
| | - Jiayu Dai
- Department of Physics, National University of Defense Technology, Changsha 410073, Hunan, China
| | - Kostya S Novoselov
- Department of Materials Science and Engineering, National University of Singapore, Singapore 117575, Singapore
- Chongqing 2D Materials Institute, Liangjiang New Area, Chongqing 400714, China
| |
Collapse
|
164
|
Wang X, Wang B, Zhang Q, Sun Y, Wang E, Luo H, Wu Y, Gu L, Li H, Liu K. Grain-Boundary Engineering of Monolayer MoS 2 for Energy-Efficient Lateral Synaptic Devices. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2102435. [PMID: 34219298 DOI: 10.1002/adma.202102435] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 04/28/2021] [Indexed: 06/13/2023]
Abstract
Synaptic devices based on 2D-layered materials have emerged as high-efficiency electronic synapses and neurons for neuromorphic computing. Lateral 2D synaptic devices have the advantages of multiple functionalities by responding to diverse stimuli, but they consume large amounts of energy, far more than the human brain. Moreover, current lateral devices employ several mechanisms based on conductive filaments and grain boundaries (GBs), but their formation is random and difficult to control, also hindering their practical applications. Here, four-terminal, lateral synaptic devices with artificially engineered GBs are reported, which are made from monolayer MoS2 . With lithography-free, direct-laser-writing-controlled MoS2 /MoS2- x Oδ GBs, such synaptic devices exhibit short-term and long-term plasticity characteristics that are responsive to electric and light stimulation simultaneously. This enables detailed simulations of biological learning and cognitive processes as well as image perception and processing. In particular, the device exhibits low energy consumption, similar to that of the human brain and much lower than those of other lateral 2D synaptic devices. This work provides an effective way to fabricate lateral synaptic devices for practical application development and sheds light on controllable electrical state switching for neuromorphic computing.
Collapse
Affiliation(s)
- Xuewen Wang
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
| | - Bolun Wang
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
| | - Qinghua Zhang
- Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Yufei Sun
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
| | - Enze Wang
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
| | - Hao Luo
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
| | - Yonghuang Wu
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
| | - Lin Gu
- Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Huanglong Li
- Department of Precision Instrument, Center for Brain Inspired Computing Research, Tsinghua University, Beijing, 100084, China
| | - Kai Liu
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
| |
Collapse
|
165
|
Zhou Y, Tao L, Chen Z, Lai H, Xie W, Xu JB. Defect Etching of Phase-Transition-Assisted CVD-Grown 2H-MoTe 2. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2102146. [PMID: 34212490 DOI: 10.1002/smll.202102146] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 04/29/2021] [Indexed: 06/13/2023]
Abstract
2D molybdenum ditelluride (MoTe2 ) with polymorphism is a promising candidate to developing phase-change memory, high-performance transistors and spintronic devices. The phase-transition-assisted chemical vapor deposition (CVD) process has been used to prepare large-scale 2H-MoTe2 with large grain size and low density of grain boundary. However, because of the lack of precise control of the growth condition, some defects including the amorphous regions and grain boundaries in 2H-MoTe2 are hardly avoidable. Here, a facile method of selectively etching defects in large-scale CVD-grown 2H-MoTe2 by triiodide ion (I3 - ) solution is reported. The defect etching is attributed to the reduced lattice symmetry, high chemisorption activity and high conductivity of the defects due to the high density of Te vacancies. The treated 2H-MoTe2 shows the suppressed hysteresis in the electrical transfer curve, enhances hole mobility and the higher effective barrier height on the metal contact, suggesting the decreased density of defects. Further chemical analysis indicates that the 2H-MoTe2 is not damaged or doped by I3 - solution during the etching process. This simple and low-cost post-processing method is effective for etching the defects in large-area 2H-MoTe2 for high-performance device applications.
Collapse
Affiliation(s)
- Yaoqiang Zhou
- Department of Electronic Engineering and Materials Science and Technology Research Center, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Li Tao
- Department of Electronic Engineering and Materials Science and Technology Research Center, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Zefeng Chen
- Department of Electronic Engineering and Materials Science and Technology Research Center, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Haojie Lai
- Siyuan Laboratory, Guangdong Provincial Engineering Technology Research Center of Vacuum Coating Technologies and New Energy Materials, Department of Physics, Jinan University, Guangzhou, 510632, China
| | - Weiguang Xie
- Siyuan Laboratory, Guangdong Provincial Engineering Technology Research Center of Vacuum Coating Technologies and New Energy Materials, Department of Physics, Jinan University, Guangzhou, 510632, China
| | - Jian-Bin Xu
- Department of Electronic Engineering and Materials Science and Technology Research Center, The Chinese University of Hong Kong, Hong Kong SAR, China
| |
Collapse
|
166
|
Abstract
Molybdenum disulfide (MoS2) is a promising transition metal dichalcogenide (TMD) that has exceptional electronic, magnetic, optical, and mechanical properties. It can be semiconducting, superconducting, or an insulator according to its polymorph. Its bandgap structure changes from indirect to direct when moving towards its nanostructures, which opens a door to bandgap engineering for MoS2. Its supercapacitive and catalytic activity was recently noticed and studied, in order to include this material in a wide range of energy applications. In this work, we present MoS2 as a future material for energy storage and generation applications, especially solar cells, which are a cornerstone for a clean and abundant source of energy. Its role in water splitting reactions can be utilized for energy generation (hydrogen evolution) and water treatment at the same time. Although MoS2 seems to be a breakthrough in the energy field, it still faces some challenges regarding its structure stability, production scalability, and manufacturing costs.
Collapse
|
167
|
Hua X, Zhang D, Kim B, Seo D, Kang K, Yang EH, Hu J, Chen X, Liang H, Watanabe K, Taniguchi T, Hone J, Kim YD, Herman IP. Stabilization of Chemical-Vapor-Deposition-Grown WS 2 Monolayers at Elevated Temperature with Hexagonal Boron Nitride Encapsulation. ACS APPLIED MATERIALS & INTERFACES 2021; 13:31271-31278. [PMID: 34170658 DOI: 10.1021/acsami.1c06348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Chemical vapor deposition (CVD)-grown flakes of high-quality monolayers of WS2 can be stabilized at elevated temperatures by encapsulation with several layer hexagonal boron nitride (h-BN), but to different degrees in the presence of ambient air, flowing N2, and flowing forming gas (95% N2, 5% H2). The best passivation of WS2 at elevated temperature occurs for h-BN-covered samples with flowing N2 (after heating to 873 K), as judged by optical microscopy and photoluminescence (PL) intensity after a heating/cooling cycle. Stability is worse for uncovered samples, but best with flowing forming gas. PL from trions, in addition to that from excitons, is seen for covered WS2 only for forming gas, during cooling below ∼323 K; the trion has an estimated binding energy of ∼28 meV. It might occur because of doping level changes caused by charge defect generation by H2 molecules diffusing between the h-BN and the SiO2/Si substrate. The decomposition of uncovered WS2 flakes in air suggests a dissociation and chemisorption energy barrier of O2 on the WS2 surface of ∼1.6 eV. Fitting the high-temperature PL intensities in air gives a binding energy of a free exciton of ∼229 meV.
Collapse
Affiliation(s)
- Xiang Hua
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027, United States
| | - Datong Zhang
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027, United States
| | - Bumho Kim
- Department of Mechanical Engineering, Columbia University, New York, New York 10027, United States
| | - Dongjea Seo
- Department of Materials Science and Engineering, Yonsei University, Seoul 120-749, Korea
- Department of Electrical and Computer Engineering, University of Minnesota,Minneapolis, Minnesota 55455, United States
| | - Kyungnam Kang
- Department of Mechanical Engineering, Stevens Institute of Technology, Hoboken, New Jersey 07030 United States
| | - Eui-Hyeok Yang
- Department of Mechanical Engineering, Stevens Institute of Technology, Hoboken, New Jersey 07030 United States
| | - Jiayang Hu
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027, United States
| | - Xianda Chen
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027, United States
| | - Haoran Liang
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027, United States
| | - Kenji Watanabe
- Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Takashi Taniguchi
- Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - James Hone
- Department of Mechanical Engineering, Columbia University, New York, New York 10027, United States
| | - Young Duck Kim
- Department of Physics, Kyung Hee University, Seoul 02447, Republic of Korea
- Department of Information Display, Kyung Hee University, Seoul 02447, Republic of Korea
- KHU-KIST Department of Converging Science and Technology, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Irving P Herman
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027, United States
| |
Collapse
|
168
|
Wang B, Peng R, Wang X, Yang Y, Wang E, Xin Z, Sun Y, Li C, Wu Y, Wei J, Sun J, Liu K. Ultrafast, Kinetically Limited, Ambient Synthesis of Vanadium Dioxides through Laser Direct Writing on Ultrathin Chalcogenide Matrix. ACS NANO 2021; 15:10502-10513. [PMID: 34009934 DOI: 10.1021/acsnano.1c03050] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Vanadium dioxide (VO2) is a strongly correlated electronic material and has attracted significant attention due to its metal-to-insulator transition and diverse smart applications. Traditional synthesis of VO2 usually requires minutes or hours of global heating and low oxygen partial pressure to achieve thermodynamic control of the valence state. Further patterning of VO2 through a series of lithography and etching processes may inevitably change its surface valence, which poses a great challenge for the assembly of micro- and nanoscale VO2-based heterojunction devices. Herein, we report an ultrafast method to simultaneously synthesize and pattern VO2 on the time scale of seconds under ambient conditions through laser direct writing on a V5S8 "canvas". The successful ambient synthesis of VO2 is attributed to the ultrafast local heating and cooling process, resulting in controlled freezing of the intermediate oxidation phase during the relatively long kinetic reaction. A Mott memristor based on a V5S8-VO2-V5S8 lateral heterostructure can be fabricated and integrated with a MoS2 channel, delivering a transistor with abrupt switching transfer characteristics. The other device with a VSxOy channel exhibits a large negative temperature coefficient of approximately 4.5%/K, which is highly desirable for microbolometers. The proposed approach enables fast and efficient integration of VO2-based heterojunction devices and is applicable to other intriguing intermediate phases of oxides.
Collapse
Affiliation(s)
- Bolun Wang
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Ruixuan Peng
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Xuewen Wang
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Yueyang Yang
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Enze Wang
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Zeqin Xin
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Yufei Sun
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Chenyu Li
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Yonghuang Wu
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Jinquan Wei
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Jingbo Sun
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Kai Liu
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| |
Collapse
|
169
|
Li S, Hong J, Gao B, Lin Y, Lim HE, Lu X, Wu J, Liu S, Tateyama Y, Sakuma Y, Tsukagoshi K, Suenaga K, Taniguchi T. Tunable Doping of Rhenium and Vanadium into Transition Metal Dichalcogenides for Two-Dimensional Electronics. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:e2004438. [PMID: 34105285 PMCID: PMC8188190 DOI: 10.1002/advs.202004438] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 01/24/2021] [Indexed: 05/27/2023]
Abstract
Two-dimensional (2D) transition metal dichalcogenides (TMDCs) with unique electrical properties are fascinating materials used for future electronics. However, the strong Fermi level pinning effect at the interface of TMDCs and metal electrodes always leads to high contact resistance, which seriously hinders their application in 2D electronics. One effective way to overcome this is to use metallic TMDCs or transferred metal electrodes as van der Waals (vdW) contacts. Alternatively, using highly conductive doped TMDCs will have a profound impact on the contact engineering of 2D electronics. Here, a novel chemical vapor deposition (CVD) using mixed molten salts is established for vapor-liquid-solid growth of high-quality rhenium (Re) and vanadium (V) doped TMDC monolayers with high controllability and reproducibility. A tunable semiconductor to metal transition is observed in the Re- and V-doped TMDCs. Electrical conductivity increases up to a factor of 108 in the degenerate V-doped WS2 and WSe2 . Using V-doped WSe2 as vdW contact, the on-state current and on/off ratio of WSe2 -based field-effect transistors have been substantially improved (from ≈10-8 to 10-5 A; ≈104 to 108 ), compared to metal contacts. Future studies on lateral contacts and interconnects using doped TMDCs will pave the way for 2D integrated circuits and flexible electronics.
Collapse
Affiliation(s)
- Shisheng Li
- International Center for Young Scientists (ICYS)National Institute for Materials Science (NIMS)Tsukuba305‐0044Japan
| | - Jinhua Hong
- Nanomaterials Research InstituteNational Institute of Advanced Industrial Science and TechnologyAIST Central 5Tsukuba305‐8564Japan
| | - Bo Gao
- Center for Green Research on Energy and Environmental Materials (GREEN)National Institute for Materials Science (NIMS)Tsukuba305‐0044Japan
- International Center for Materials Nanoarchitectonics (WPI‐MANA)National Institute for Materials Science (NIMS)Tsukuba305‐0044Japan
| | - Yung‐Chang Lin
- Nanomaterials Research InstituteNational Institute of Advanced Industrial Science and TechnologyAIST Central 5Tsukuba305‐8564Japan
| | - Hong En Lim
- Department of PhysicsTokyo Metropolitan UniversityHachioji192‐0397Japan
| | - Xueyi Lu
- International Center for Materials Nanoarchitectonics (WPI‐MANA)National Institute for Materials Science (NIMS)Tsukuba305‐0044Japan
| | - Jing Wu
- Institute of Materials Research and EngineeringAgency for ScienceTechnology and ResearchSingapore138634Singapore
| | - Song Liu
- Institute of Chemical Biology and Nanomedicine (ICBN)College of Chemistry and Chemical EngineeringHunan UniversityChangsha410082P. R. China
| | - Yoshitaka Tateyama
- Center for Green Research on Energy and Environmental Materials (GREEN)National Institute for Materials Science (NIMS)Tsukuba305‐0044Japan
- International Center for Materials Nanoarchitectonics (WPI‐MANA)National Institute for Materials Science (NIMS)Tsukuba305‐0044Japan
| | - Yoshiki Sakuma
- Research Center for Functional MaterialsNational Institute for Materials Science (NIMS)Tsukuba305‐0044Japan
| | - Kazuhito Tsukagoshi
- International Center for Materials Nanoarchitectonics (WPI‐MANA)National Institute for Materials Science (NIMS)Tsukuba305‐0044Japan
| | - Kazu Suenaga
- Nanomaterials Research InstituteNational Institute of Advanced Industrial Science and TechnologyAIST Central 5Tsukuba305‐8564Japan
| | - Takaaki Taniguchi
- International Center for Materials Nanoarchitectonics (WPI‐MANA)National Institute for Materials Science (NIMS)Tsukuba305‐0044Japan
| |
Collapse
|
170
|
Zhou J, Xu H, Shi Y, Li J. Terahertz Driven Reversible Topological Phase Transition of Monolayer Transition Metal Dichalcogenides. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:e2003832. [PMID: 34165897 PMCID: PMC8224436 DOI: 10.1002/advs.202003832] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 02/01/2021] [Indexed: 05/12/2023]
Abstract
This paper shows how terahertz light can drive ultrafast topological phase transitions in monolayer transition metal dichalcogenides (TMDs). The phase transition is induced by the light interaction with both electron and phonon subsystems in the material. The mechanism of such a phase transition is formulated by thermodynamics theory: the Gibbs free energy landscape can be effectively modulated under light, and the relative stability between different (meta-)stable phases can be switched. This mechanism is applied to TMDs and reversible phase transitions between the topologically trivial 2H and nontrivial 1T' phases are predicted, providing appropriate light frequency, polarization, and intensity are applied. The large energy barrier on the martensitic transformation path can be significantly reduced, yielding a small energy barrier phase transition with fast kinetics. Compared with other phase transition schemes, light illumination has great advantages, such as its non-contact nature and easy tunability. The reversible topological phase transition can be applicable in high-resolution fast data storage and in-memory computing devices.
Collapse
Affiliation(s)
- Jian Zhou
- Center for Alloy Innovation and DesignCenter for Advancing Materials Performance from the NanoscaleState Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
| | - Haowei Xu
- Department of Nuclear Science and EngineeringMassachusetts Institute of TechnologyCambridgeMA02139USA
| | - Yongliang Shi
- Center for Spintronics and Quantum SystemsState Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
| | - Ju Li
- Department of Nuclear Science and EngineeringMassachusetts Institute of TechnologyCambridgeMA02139USA
- Department of Materials Science and EngineeringMassachusetts Institute of TechnologyCambridgeMA02139USA
| |
Collapse
|
171
|
Zhang L, Dong J, Ding F. Strategies, Status, and Challenges in Wafer Scale Single Crystalline Two-Dimensional Materials Synthesis. Chem Rev 2021; 121:6321-6372. [PMID: 34047544 DOI: 10.1021/acs.chemrev.0c01191] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The successful exfoliation of graphene has given a tremendous boost to research on various two-dimensional (2D) materials in the last 15 years. Different from traditional thin films, a 2D material is composed of one to a few atomic layers. While atoms within a layer are chemically bonded, interactions between layers are generally weak van der Waals (vdW) interactions. Due to their particular dimensionality, 2D materials exhibit special electronic, magnetic, mechanical, and thermal properties, not found in their 3D counterparts, and therefore they have great potential in various applications, such as 2D materials-based devices. To fully realize their large-scale practical applications, especially in devices, wafer scale single crystalline (WSSC) 2D materials are indispensable. In this review, we present a detailed overview on strategies toward the synthesis of WSSC 2D materials while highlighting the recent progress on WSSC graphene, hexagonal boron nitride (hBN), and transition metal dichalcogenide (TMDC) synthesis. The challenges that need to be addressed in future studies have also been described. In general, there have been two distinct routes to synthesize WSSC 2D materials: (i) allowing only one nucleus on a wafer scale substrate to be formed and developed into a large single crystal and (ii) seamlessly stitching a large number of unidirectionally aligned 2D islands on a wafer scale substrate, which is generally single crystalline. Currently, the synthesis of WSSC graphene has been realized by both routes, and WSSC hBN and MoS2 have been synthesized by route (ii). On the other hand, the growth of other WSSC 2D materials and WSSC multilayer 2D materials still remains a big challenge. In the last section, we wrap up this review by summarizing the future challenges and opportunities in the synthesis of various WSSC 2D materials.
Collapse
Affiliation(s)
- Leining Zhang
- Centre for Multidimensional Carbon Materials, Institute for Basic Science, Ulsan 44919, South Korea.,School of Materials Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, South Korea
| | - Jichen Dong
- Centre for Multidimensional Carbon Materials, Institute for Basic Science, Ulsan 44919, South Korea.,Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Feng Ding
- Centre for Multidimensional Carbon Materials, Institute for Basic Science, Ulsan 44919, South Korea.,School of Materials Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, South Korea
| |
Collapse
|
172
|
Adhikari B, Limbu TB, Vinodgopal K, Yan F. Atmospheric-pressure CVD growth of two-dimensional 2H- and 1 T'-MoTe 2films with high-performance SERS activity. NANOTECHNOLOGY 2021; 32:335701. [PMID: 33971633 DOI: 10.1088/1361-6528/abff8f] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Accepted: 05/10/2021] [Indexed: 06/12/2023]
Abstract
Two-dimensional (2D) molybdenum ditelluride (MoTe2) is a member of the transition-metal dichalcogenides family, which is an especially promising platform for surface-enhanced Raman scattering (SERS) applications, due to its excellent electronic properties. However, the synthesis of large-area highly crystalline 2D MoTe2with controllable polymorphism is a huge challenge due to the small free energy difference (∼40 meV per unit cell) between semiconducting 2H-MoTe2and semi-metallic 1 T'-MoTe2. Herein, we report an optimized route for the synthesis of 2H- and 1 T'-MoTe2films by atmospheric-pressure chemical vapor deposition. The SERS study of the as-grown MoTe2films was carried out using methylene blue (MB) as a probe molecule. The Raman enhancement factor on 1 T'-MoTe2was found to be three times higher than that on 2H-MoTe2and the 1 T'-MoTe2film is an efficient Raman-enhancing substrate that can be used to detect MB at nanomolar concentrations. Our study also imparts knowledge on the significance of a suitable combination of laser excitation wavelength and molecule-material platform for achieving ultrasensitive SERS-based chemical detection.
Collapse
Affiliation(s)
- Bikram Adhikari
- Department of Chemistry and Biochemistry, North Carolina Central University, Durham, NC 27707, United States of America
| | - Tej B Limbu
- Department of Chemistry and Biochemistry, North Carolina Central University, Durham, NC 27707, United States of America
| | - Kizhanipuram Vinodgopal
- Department of Chemistry and Biochemistry, North Carolina Central University, Durham, NC 27707, United States of America
| | - Fei Yan
- Department of Chemistry and Biochemistry, North Carolina Central University, Durham, NC 27707, United States of America
| |
Collapse
|
173
|
Zhang JJ, Altalhi T, Yang JH, Yakobson BI. Semiconducting α'-boron sheet with high mobility and low all-boron contact resistance: a first-principles study. NANOSCALE 2021; 13:8474-8480. [PMID: 33984112 DOI: 10.1039/d1nr00329a] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Two-dimensional field effect transistors (2D FETs) with high mobility semiconducting channels and low contact resistance between the semiconducting channel and the metallic electrodes are highly sought components of future electronics. Recently, 2D boron sheets (borophene) offer a great platform for realizing ideal 2D FETs but stable semiconducting phases still remain much unexplored. Herein, based on first-principles calculations and tight-binding model, we first clarify that α'-boron is the most stable semiconductor phase of boron sheets, while reveal the mechanism of metal-to-semiconductor transition from α- to α'-boron. Then we demonstrate that the carrier mobility in α'- and metastable β3S-boron should be very high, due to small effective masses of electrons and holes, as a good candidate material for 2D FETs. Considering further the lateral contacts between semiconducting α' and metallic borophene, we find that the α'- and β3S-boron sheet can form Ohmic contacts with selected metallic boron sheets, without Schottky barrier. The high energetic stability and excellent mobility properties of α'-boron sheet together with its good contact match to metallic borophene electrodes are promising for fully boron-based FETs in the real 2D atomically thin limit.
Collapse
Affiliation(s)
- Jun-Jie Zhang
- Department of Material Science & NanoEngineering, Rice University, Houston, Texas 77005, USA.
| | - Tariq Altalhi
- Chemistry Department, Taif University, Taif, Saudi Arabia.
| | - Ji-Hui Yang
- Department of Material Science & NanoEngineering, Rice University, Houston, Texas 77005, USA.
| | - Boris I Yakobson
- Chemistry Department, Taif University, Taif, Saudi Arabia. and Department of Chemistry, Rice University, Houston, Texas 77005, USA
| |
Collapse
|
174
|
Lee G, Baek JH, Ren F, Pearton SJ, Lee GH, Kim J. Artificial Neuron and Synapse Devices Based on 2D Materials. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2100640. [PMID: 33817985 DOI: 10.1002/smll.202100640] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 03/05/2021] [Indexed: 06/12/2023]
Abstract
Neuromorphic systems, which emulate neural functionalities of a human brain, are considered to be an attractive next-generation computing approach, with advantages of high energy efficiency and fast computing speed. After these neuromorphic systems are proposed, it is demonstrated that artificial synapses and neurons can mimic neural functions of biological synapses and neurons. However, since the neuromorphic functionalities are highly related to the surface properties of materials, bulk material-based neuromorphic devices suffer from uncontrollable defects at surfaces and strong scattering caused by dangling bonds. Therefore, 2D materials which have dangling-bond-free surfaces and excellent crystallinity have emerged as promising candidates for neuromorphic computing hardware. First, the fundamental synaptic behavior is reviewed, such as synaptic plasticity and learning rule, and requirements of artificial synapses to emulate biological synapses. In addition, an overview of recent advances on 2D materials-based synaptic devices is summarized by categorizing these into various working principles of artificial synapses. Second, the compulsory behavior and requirements of artificial neurons such as the all-or-nothing law and refractory periods to simulate a spike neural network are described, and the implementation of 2D materials-based artificial neurons to date is reviewed. Finally, future challenges and outlooks of 2D materials-based neuromorphic devices are discussed.
Collapse
Affiliation(s)
- Geonyeop Lee
- Department of Chemical and Biological Engineering, Korea University, Seoul, 02841, Korea
| | - Ji-Hwan Baek
- Department of Material Science and Engineering, Seoul National University, Seoul, 08826, Korea
| | - Fan Ren
- Department of Chemical Engineering, University of Florida, Gainesville, FL, 32611, USA
| | - Stephen J Pearton
- Department of Materials Science and Engineering, University of Florida, Gainesville, FL, 32611, USA
| | - Gwan-Hyoung Lee
- Department of Material Science and Engineering, Seoul National University, Seoul, 08826, Korea
- Research Institute of Advanced Materials, Seoul National University, Seoul, 08826, Korea
- Institute of Engineering Research, Seoul National University, Seoul, 08826, Korea
- Institute of Applied Physics, Seoul National University, Seoul, 08826, Korea
| | - Jihyun Kim
- Department of Chemical and Biological Engineering, Korea University, Seoul, 02841, Korea
| |
Collapse
|
175
|
Zhao Y, Li Y, He S, Ma F. Semiconductor-semimetal transition of MoTe2 monolayer modulated by charge-injection and strain engineering. Chem Phys Lett 2021. [DOI: 10.1016/j.cplett.2021.138473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
176
|
Li Y, Wang M, Yi Y, Lu C, Dou S, Sun J. Metallic Transition Metal Dichalcogenides of Group VIB: Preparation, Stabilization, and Energy Applications. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2005573. [PMID: 33734605 DOI: 10.1002/smll.202005573] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 10/21/2020] [Indexed: 06/12/2023]
Abstract
Layered transition metal dichalcogenides (TMDs) of group VIB have been widely used in the realms of energy storage and conversions. Along with the existence of semiconducting states, their metallic phases have recently attracted numerous attentions owing to their fascinating physical and chemical properties. Many efforts have been devoted to obtain metallic TMDs with high purity and yield. Nevertheless, such metallic phase is thermodynamically metastable and tends to convert into semiconducting phase, which necessitates the exploration over effective strategies to ensure the stability. In this review, typical fabrication routes are introduced and those critical factors during preparation are elaborately discussed. Moreover, the stabilized strategies are summarized with concrete examples highlighting the key mechanisms toward efficient stabilization. Finally, emerging energy applications are overviewed. This review presents comprehensive research status of metallic group VIB TMDs, aiming to facilitate further scientific investigations and promote future practical applications in the fields of energy storage and conversion.
Collapse
Affiliation(s)
- Yihui Li
- College of Energy, Soochow Institute for Energy and Materials InnovationS (SIEMIS), Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, 688 Moye Road, Suzhou, 215006, P. R. China
| | - Menglei Wang
- College of Energy, Soochow Institute for Energy and Materials InnovationS (SIEMIS), Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, 688 Moye Road, Suzhou, 215006, P. R. China
| | - Yuyang Yi
- College of Energy, Soochow Institute for Energy and Materials InnovationS (SIEMIS), Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, 688 Moye Road, Suzhou, 215006, P. R. China
| | - Chen Lu
- College of Energy, Soochow Institute for Energy and Materials InnovationS (SIEMIS), Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, 688 Moye Road, Suzhou, 215006, P. R. China
- Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Shixue Dou
- Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong, NSW, 2522, Australia
| | - Jingyu Sun
- College of Energy, Soochow Institute for Energy and Materials InnovationS (SIEMIS), Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, 688 Moye Road, Suzhou, 215006, P. R. China
| |
Collapse
|
177
|
Rao T, Wang H, Zeng Y, Guo Z, Zhang H, Liao W. Phase Transitions and Water Splitting Applications of 2D Transition Metal Dichalcogenides and Metal Phosphorous Trichalcogenides. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:2002284. [PMID: 34026429 PMCID: PMC8132069 DOI: 10.1002/advs.202002284] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 01/24/2021] [Indexed: 06/02/2023]
Abstract
2D layered materials turn out to be the most attractive hotspot in materials for their unique physical and chemical properties. A special class of 2D layered material refers to materials exhibiting phase transition based on environment variables. Among these materials, transition metal dichalcogenides (TMDs) act as a promising alternative for their unique combination of atomic-scale thickness, direct bandgap, significant spin-orbit coupling and prominent electronic and mechanical properties, enabling them to be applied for fundamental studies as catalyst materials. Metal phosphorous trichalcogenides (MPTs), as another potential catalytic 2D phase transition material, have been employed for their unusual intercalation behavior and electrochemical properties, which act as a secondary electrode in lithium batteries. The preparation of 2D TMD and MPT materials has been extensively conducted by engineering their intrinsic structures at the atomic scale. In this study, advanced synthesis methods of preparing 2D TMD and MPT materials are tested, and their properties are investigated, with stress placed on their phase transition. The surge of this type of report is associated with water-splitting catalysis and other catalytic purposes. This study aims to be a guideline to explore the mentioned 2D TMD and MPT materials for their catalytic applications.
Collapse
Affiliation(s)
- Tingke Rao
- College of Electronic and Information EngineeringInstitute of Microscale OptoelectronicsShenzhen UniversityShenzhen518060P. R. China
| | - Huide Wang
- Institute of Microscale OptoelectronicsCollege of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen518060P. R. China
| | - Yu‐Jia Zeng
- Institute of Microscale OptoelectronicsCollege of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen518060P. R. China
| | - Zhinan Guo
- Institute of Microscale OptoelectronicsCollege of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen518060P. R. China
| | - Han Zhang
- Institute of Microscale OptoelectronicsCollege of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen518060P. R. China
| | - Wugang Liao
- College of Electronic and Information EngineeringInstitute of Microscale OptoelectronicsShenzhen UniversityShenzhen518060P. R. China
| |
Collapse
|
178
|
Seo SY, Yang DH, Moon G, Okello OFN, Park MY, Lee SH, Choi SY, Jo MH. Identification of Point Defects in Atomically Thin Transition-Metal Dichalcogenide Semiconductors as Active Dopants. NANO LETTERS 2021; 21:3341-3354. [PMID: 33825482 DOI: 10.1021/acs.nanolett.0c05135] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Selective doping in semiconductors is essential not only for monolithic integrated circuity fabrications but also for tailoring their properties including electronic, optical, and catalytic activities. Such active dopants are essentially point defects in the host lattice. In atomically thin two-dimensional (2D) transition-metal dichalcogenides (TMDCs), the roles of such point defects are particularly critical in addition to their large surface-to-volume ratio, because their bond dissociation energy is relatively weaker, compared to elemental semiconductors. In this Mini Review, we review recent advances in the identifications of diverse point defects in 2D TMDC semiconductors, as active dopants, toward the tunable doping processes, along with the doping methods and mechanisms in literature. In particular, we discuss key issues in identifying such dopants both at the atomic scales and the device scales with selective examples. Fundamental understanding of these point defects can hold promise for tunability doping of atomically thin 2D semiconductor platforms.
Collapse
|
179
|
Wang Y, Liu S, Li Q, Quhe R, Yang C, Guo Y, Zhang X, Pan Y, Li J, Zhang H, Xu L, Shi B, Tang H, Li Y, Yang J, Zhang Z, Xiao L, Pan F, Lu J. Schottky barrier heights in two-dimensional field-effect transistors: from theory to experiment. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2021; 84:056501. [PMID: 33761489 DOI: 10.1088/1361-6633/abf1d4] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Accepted: 03/24/2021] [Indexed: 06/12/2023]
Abstract
Over the past decade, two-dimensional semiconductors (2DSCs) have aroused wide interest due to their extraordinary electronic, magnetic, optical, mechanical, and thermal properties, which hold potential in electronic, optoelectronic, thermoelectric applications, and so forth. The field-effect transistor (FET), a semiconductor gated with at least three terminals, is pervasively exploited as the device geometry for these applications. For lack of effective and stable substitutional doping techniques, direct metal contact is often used in 2DSC FETs to inject carriers. A Schottky barrier (SB) generally exists in the metal-2DSC junction, which significantly affects and even dominates the performance of most 2DSC FETs. Therefore, low SB or Ohmic contact is highly preferred for approaching the intrinsic characteristics of the 2DSC channel. In this review, we systematically introduce the recent progress made in theoretical prediction of the SB height (SBH) in the 2DSC FETs and the efforts made both in theory and experiments to achieve low SB contacts. From the comparison between the theoretical and experimentally observed SBHs, the emerging first-principles quantum transport simulation turns out to be the most powerful theoretical tool to calculate the SBH of a 2DSC FET. Finally, we conclude this review from the viewpoints of state-of-the-art electrode designs for 2DSC FETs.
Collapse
Affiliation(s)
- Yangyang Wang
- Nanophotonics and Optoelectronics Research Center, Qian Xuesen Laboratory of Space Technology, China Academy of Space Technology, Beijing 100094, People's Republic of China
| | - Shiqi Liu
- State Key Laboratory for Mesoscopic Physics and Department of Physics, Peking University, Beijing 100871, People's Republic of China
| | - Qiuhui Li
- State Key Laboratory for Mesoscopic Physics and Department of Physics, Peking University, Beijing 100871, People's Republic of China
| | - Ruge Quhe
- State Key Laboratory of Information Photonics and Optical Communications and School of Science, Beijing University of Posts and Telecommunications, Beijing 100876, People's Republic of China
| | - Chen Yang
- State Key Laboratory for Mesoscopic Physics and Department of Physics, Peking University, Beijing 100871, People's Republic of China
| | - Ying Guo
- School of Physics and Telecommunication Engineering, Shaanxi Key Laboratory of Catalysis, Shaanxi University of Technology, Hanzhong 723001, People's Republic of China
| | - Xiuying Zhang
- State Key Laboratory for Mesoscopic Physics and Department of Physics, Peking University, Beijing 100871, People's Republic of China
| | - Yuanyuan Pan
- State Key Laboratory of Heavy Oil Processing, Institute of New Energy, College of Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, People's Republic of China
| | - Jingzhen Li
- State Key Laboratory for Mesoscopic Physics and Department of Physics, Peking University, Beijing 100871, People's Republic of China
| | - Han Zhang
- School of Information Science and Technology, Northwest University, Xi'an, 710127, People's Republic of China
| | - Lin Xu
- Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics, Peking University, Beijing 100871, People's Republic of China
| | - Bowen Shi
- State Key Laboratory for Mesoscopic Physics and Department of Physics, Peking University, Beijing 100871, People's Republic of China
| | - Hao Tang
- State Key Laboratory for Mesoscopic Physics and Department of Physics, Peking University, Beijing 100871, People's Republic of China
| | - Ying Li
- State Key Laboratory for Mesoscopic Physics and Department of Physics, Peking University, Beijing 100871, People's Republic of China
| | - Jinbo Yang
- State Key Laboratory for Mesoscopic Physics and Department of Physics, Peking University, Beijing 100871, People's Republic of China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, People's Republic of China
- Beijing Key Laboratory for Magnetoelectric Materials and Devices (BKL-MEMD), Beijing 100871, People's Republic of China
| | - Zhiyong Zhang
- Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics, Peking University, Beijing 100871, People's Republic of China
| | - Lin Xiao
- Nanophotonics and Optoelectronics Research Center, Qian Xuesen Laboratory of Space Technology, China Academy of Space Technology, Beijing 100094, People's Republic of China
| | - Feng Pan
- School of Advanced Materials, Peking University, Shenzhen Graduate School, Shenzhen 518055, People's Republic of China
| | - Jing Lu
- State Key Laboratory for Mesoscopic Physics and Department of Physics, Peking University, Beijing 100871, People's Republic of China
- Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics, Peking University, Beijing 100871, People's Republic of China
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, People's Republic of China
- Beijing Key Laboratory for Magnetoelectric Materials and Devices (BKL-MEMD), Beijing 100871, People's Republic of China
| |
Collapse
|
180
|
He F, Zhou Y, Ye Z, Cho SH, Jeong J, Meng X, Wang Y. Moiré Patterns in 2D Materials: A Review. ACS NANO 2021; 15:5944-5958. [PMID: 33769797 DOI: 10.1021/acsnano.0c10435] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Quantum materials have attracted much attention in recent years due to their exotic and incredible properties. Among them, van der Waals materials stand out due to their weak interlayer coupling, providing easy access to manipulating electrical and optical properties. Many fascinating electrical, optical, and magnetic properties have been reported in the moiré superlattices, such as unconventional superconductivity, photonic dispersion engineering, and ferromagnetism. In this review, we summarize the methods to prepare moiré superlattices in the van der Waals materials and focus on the current discoveries of moiré pattern-modified electrical properties, recent findings of atomic reconstruction, as well as some possible future directions in this field.
Collapse
Affiliation(s)
- Feng He
- State Key Laboratory on Tunable Laser Technology, School of Electronic and Information Engineering, Harbin Institute of Technology, Shenzhen 518055, China
- Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
- Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Yongjian Zhou
- Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Zefang Ye
- Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Sang-Hyeok Cho
- Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Jihoon Jeong
- Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Xianghai Meng
- Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Yaguo Wang
- Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
- Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712, United States
| |
Collapse
|
181
|
Chen J, Zhou Z, Liu H, Bian C, Zou Y, Wang Z, Zhao Z, Wu K, Yang H, Shen C, Cheng ZG, Bao L, Gao HJ. One-dimensional weak antilocalization effect in 1T'-MoTe 2nanowires grown by chemical vapor deposition. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:185701. [PMID: 33730711 DOI: 10.1088/1361-648x/abef99] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 03/17/2021] [Indexed: 06/12/2023]
Abstract
We present a chemical vapor deposition method for the synthesizing of single-crystal 1T'-MoTe2nanowires and the observation of one-dimensional weak antilocalization effect in 1T'-MoTe2nanowires for the first time. The diameters of the 1T'-MoTe2nanowires can be controlled by changing the flux of H2/Ar carrier gas. Spherical-aberration-corrected transmission electron microscopy, selected area electron diffraction and energy dispersive x-ray spectroscopy (EDS) reveal the 1T' phase and the atomic ratio of Te/Mo closing to 2:1. The resistivity of 1T'-MoTe2nanowires shows metallic behavior and agrees well with the Fermi liquid theory (<20 K). The coherence length extracted from 1D Hikami-Larkin-Nagaoka model with the presence of strong spin-orbit coupling is proportional toT-0.36, indicating a Nyquist electron-electron interaction dephasing mechanism at one dimension. These results provide a feasible way to prepare one-dimensional topological materials and is promising for fundamental study of the transport properties.
Collapse
Affiliation(s)
- Jiancui Chen
- Institute of Physics, Chinese Academy of Sciences, PO Box 603, Beijing 100190, People's Republic of China
- University of Chinese Academy of Sciences and CAS Center for Excellence in Topological Quantum Computation, Chinese Academy of Sciences, PO Box 603, Beijing 100190, People's Republic of China
| | - Zhang Zhou
- Institute of Physics, Chinese Academy of Sciences, PO Box 603, Beijing 100190, People's Republic of China
- University of Chinese Academy of Sciences and CAS Center for Excellence in Topological Quantum Computation, Chinese Academy of Sciences, PO Box 603, Beijing 100190, People's Republic of China
| | - Hongtao Liu
- Institute of Physics, Chinese Academy of Sciences, PO Box 603, Beijing 100190, People's Republic of China
- University of Chinese Academy of Sciences and CAS Center for Excellence in Topological Quantum Computation, Chinese Academy of Sciences, PO Box 603, Beijing 100190, People's Republic of China
| | - Ce Bian
- Institute of Physics, Chinese Academy of Sciences, PO Box 603, Beijing 100190, People's Republic of China
- University of Chinese Academy of Sciences and CAS Center for Excellence in Topological Quantum Computation, Chinese Academy of Sciences, PO Box 603, Beijing 100190, People's Republic of China
| | - Yuting Zou
- Institute of Physics, Chinese Academy of Sciences, PO Box 603, Beijing 100190, People's Republic of China
- University of Chinese Academy of Sciences and CAS Center for Excellence in Topological Quantum Computation, Chinese Academy of Sciences, PO Box 603, Beijing 100190, People's Republic of China
| | - Zhenyu Wang
- Institute of Physics, Chinese Academy of Sciences, PO Box 603, Beijing 100190, People's Republic of China
- University of Chinese Academy of Sciences and CAS Center for Excellence in Topological Quantum Computation, Chinese Academy of Sciences, PO Box 603, Beijing 100190, People's Republic of China
| | - Zhen Zhao
- Institute of Physics, Chinese Academy of Sciences, PO Box 603, Beijing 100190, People's Republic of China
- University of Chinese Academy of Sciences and CAS Center for Excellence in Topological Quantum Computation, Chinese Academy of Sciences, PO Box 603, Beijing 100190, People's Republic of China
| | - Kang Wu
- Institute of Physics, Chinese Academy of Sciences, PO Box 603, Beijing 100190, People's Republic of China
- University of Chinese Academy of Sciences and CAS Center for Excellence in Topological Quantum Computation, Chinese Academy of Sciences, PO Box 603, Beijing 100190, People's Republic of China
| | - Haitao Yang
- Institute of Physics, Chinese Academy of Sciences, PO Box 603, Beijing 100190, People's Republic of China
- University of Chinese Academy of Sciences and CAS Center for Excellence in Topological Quantum Computation, Chinese Academy of Sciences, PO Box 603, Beijing 100190, People's Republic of China
- Songshan Lake Materials Laboratory, Dongguan 523808, Guangdong, People's Republic of China
| | - Chengmin Shen
- Institute of Physics, Chinese Academy of Sciences, PO Box 603, Beijing 100190, People's Republic of China
- University of Chinese Academy of Sciences and CAS Center for Excellence in Topological Quantum Computation, Chinese Academy of Sciences, PO Box 603, Beijing 100190, People's Republic of China
- Songshan Lake Materials Laboratory, Dongguan 523808, Guangdong, People's Republic of China
| | - Zhi Gang Cheng
- Institute of Physics, Chinese Academy of Sciences, PO Box 603, Beijing 100190, People's Republic of China
- University of Chinese Academy of Sciences and CAS Center for Excellence in Topological Quantum Computation, Chinese Academy of Sciences, PO Box 603, Beijing 100190, People's Republic of China
| | - Lihong Bao
- Institute of Physics, Chinese Academy of Sciences, PO Box 603, Beijing 100190, People's Republic of China
- University of Chinese Academy of Sciences and CAS Center for Excellence in Topological Quantum Computation, Chinese Academy of Sciences, PO Box 603, Beijing 100190, People's Republic of China
- Songshan Lake Materials Laboratory, Dongguan 523808, Guangdong, People's Republic of China
| | - Hong-Jun Gao
- Institute of Physics, Chinese Academy of Sciences, PO Box 603, Beijing 100190, People's Republic of China
- University of Chinese Academy of Sciences and CAS Center for Excellence in Topological Quantum Computation, Chinese Academy of Sciences, PO Box 603, Beijing 100190, People's Republic of China
- Songshan Lake Materials Laboratory, Dongguan 523808, Guangdong, People's Republic of China
| |
Collapse
|
182
|
Ling F, Xia W, Li L, Zhou X, Luo X, Bu Q, Huang J, Liu X, Kang W, Zhou M. Single Transition Metal Atom Bound to the Unconventional Phase of the MoS 2 Monolayer for Catalytic Oxygen Reduction Reaction: A First-Principles Study. ACS APPLIED MATERIALS & INTERFACES 2021; 13:17412-17419. [PMID: 33844514 DOI: 10.1021/acsami.0c21597] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Supported single-atom catalysts (SACs) have received a lot of attention due to their super-high atom utilization and outstanding catalytic performance. However, the instability of the supported transition-metal (TM) atoms hampers their widespread applications. Exploration of an appropriate substrate to stabilize the supported single atom is crucial for the future implementation of SACs. In recent years, two-dimensional materials have been proposed as possible substrates due to their large specific surface areas, but their chemically inert surfaces are difficult to stabilize TM atoms without defecting or doping. Herein, by means of systematic first-principles calculations, we demonstrate that the defect-free MoS2 monolayer in the unconventional phase (1T') can effectively immobilize single TM atoms owing to its unique electrophilic property as compared to the conventional 2H phase. As a prototype probe, we investigated oxygen reduction reaction (ORR) catalyzed by a total of 21 single TM atoms stabilized on 1T'-MoS2 and successfully screened out two candidates, Cu and Pd@1T'-MoS2, which have a low overpotential of 0.41 and 0.32 V respectively, outperforming most of the previously reported ORR catalysts. Furthermore, we reveal that the adsorption energy of the ORR intermediate, *OH, provides an excellent descriptor to assess the ORR activity, which is further determined by the d-band center of the supported TM adatoms, thus being a great advantage for future design of stable and high-performance SACs.
Collapse
Affiliation(s)
- Faling Ling
- School of Science, Chongqing University of Posts and Telecommunications, Chongqing 400065, P. R. China
| | - Weidi Xia
- School of Science, Chongqing University of Posts and Telecommunications, Chongqing 400065, P. R. China
| | - Li Li
- School of Science, Chongqing University of Posts and Telecommunications, Chongqing 400065, P. R. China
| | - Xianju Zhou
- School of Science, Chongqing University of Posts and Telecommunications, Chongqing 400065, P. R. China
| | - Xu Luo
- School of Science, Chongqing University of Posts and Telecommunications, Chongqing 400065, P. R. China
| | - Qingzhou Bu
- School of Science, Chongqing University of Posts and Telecommunications, Chongqing 400065, P. R. China
| | - Jiacai Huang
- School of Science, Chongqing University of Posts and Telecommunications, Chongqing 400065, P. R. China
| | - Xiaoqing Liu
- College of Optoelectronic Engineering, Chongqing University, Chongqing 400044, P. R. China
| | - Wei Kang
- College of Optoelectronic Engineering, Chongqing University, Chongqing 400044, P. R. China
| | - Miao Zhou
- College of Optoelectronic Engineering, Chongqing University, Chongqing 400044, P. R. China
| |
Collapse
|
183
|
Lv L, Yu J, Hu M, Yin S, Zhuge F, Ma Y, Zhai T. Design and tailoring of two-dimensional Schottky, PN and tunnelling junctions for electronics and optoelectronics. NANOSCALE 2021; 13:6713-6751. [PMID: 33885475 DOI: 10.1039/d1nr00318f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Owing to their superior carrier mobility, strong light-matter interactions, and flexibility at the atomically thin thickness, two-dimensional (2D) materials are attracting wide interest for application in electronic and optoelectronic devices, including rectifying diodes, transistors, memory, photodetectors, and light-emitting diodes. At the heart of these devices, Schottky, PN, and tunneling junctions are playing an essential role in defining device function. Intriguingly, the ultrathin thickness and unique van der Waals (vdW) interlayer coupling in 2D materials has rendered enormous opportunities for the design and tailoring of various 2D junctions, e.g. using Lego-like hetero-stacking, surface decoration, and field-effect modulation methods. Such flexibility has led to marvelous breakthroughs during the exploration of 2D electronics and optoelectronic devices. To advance further, it is imperative to provide an overview of existing strategies for the engineering of various 2D junctions for their integration in the future. Thus, in this review, we provide a comprehensive survey of previous efforts toward 2D Schottky, PN, and tunneling junctions, and the functional devices built from them. Though these junctions exhibit similar configurations, distinct strategies have been developed for their optimal figures of merit based on their working principles and functional purposes.
Collapse
Affiliation(s)
- Liang Lv
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China.
| | | | | | | | | | | | | |
Collapse
|
184
|
Xu X, Pan Y, Liu S, Han B, Gu P, Li S, Xu W, Peng Y, Han Z, Chen J, Gao P, Ye Y. Seeded 2D epitaxy of large-area single-crystal films of the van der Waals semiconductor 2H MoTe 2. Science 2021; 372:195-200. [PMID: 33833124 DOI: 10.1126/science.abf5825] [Citation(s) in RCA: 87] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 03/04/2021] [Indexed: 12/23/2022]
Abstract
The integration of two-dimensional (2D) van der Waals semiconductors into silicon electronics technology will require the production of large-scale, uniform, and highly crystalline films. We report a route for synthesizing wafer-scale single-crystalline 2H molybdenum ditelluride (MoTe2) semiconductors on an amorphous insulating substrate. In-plane 2D-epitaxy growth by tellurizing was triggered from a deliberately implanted single seed crystal. The resulting single-crystalline film completely covered a 2.5-centimeter wafer with excellent uniformity. The 2H MoTe2 2D single-crystalline film can use itself as a template for further rapid epitaxy in a vertical manner. Transistor arrays fabricated with the as-prepared 2H MoTe2 single crystals exhibited high electrical performance, with excellent uniformity and 100% device yield.
Collapse
Affiliation(s)
- Xiaolong Xu
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-Optoelectronics, School of Physics, Peking University, Beijing 100871, China.,Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
| | - Yu Pan
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-Optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Shuai Liu
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-Optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Bo Han
- Electron Microscopy Laboratory, School of Physics, Peking University, Beijing 100871, China.,International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Pingfan Gu
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-Optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Siheng Li
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Wanjin Xu
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-Optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Yuxuan Peng
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-Optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Zheng Han
- State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Opto-Electronics, Shanxi University, Taiyuan 03006, China.,Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 03006, China
| | - Ji Chen
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-Optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Peng Gao
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China.,Electron Microscopy Laboratory, School of Physics, Peking University, Beijing 100871, China.,International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Yu Ye
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-Optoelectronics, School of Physics, Peking University, Beijing 100871, China. .,Collaborative Innovation Center of Quantum Matter, Beijing 100871, China.,Peking University Yangtze Delta Institute of Optoelectronics, Nantong 226010, Jiangsu, China
| |
Collapse
|
185
|
Liu QM, Wu D, Li ZA, Shi LY, Wang ZX, Zhang SJ, Lin T, Hu TC, Tian HF, Li JQ, Dong T, Wang NL. Photoinduced multistage phase transitions in Ta 2NiSe 5. Nat Commun 2021; 12:2050. [PMID: 33824351 PMCID: PMC8024274 DOI: 10.1038/s41467-021-22345-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 03/10/2021] [Indexed: 02/01/2023] Open
Abstract
Ultrafast control of material physical properties represents a rapidly developing field in condensed matter physics. Yet, accessing the long-lived photoinduced electronic states is still in its early stages, especially with respect to an insulator to metal phase transition. Here, by combining transport measurement with ultrashort photoexcitation and coherent phonon spectroscopy, we report on photoinduced multistage phase transitions in Ta2NiSe5. Upon excitation by weak pulse intensity, the system is triggered to a short-lived state accompanied by a structural change. Further increasing the excitation intensity beyond a threshold, a photoinduced steady new state is achieved where the resistivity drops by more than four orders at temperature 50 K. This new state is thermally stable up to at least 350 K and exhibits a lattice structure different from any of the thermally accessible equilibrium states. Transmission electron microscopy reveals an in-chain Ta atom displacement in the photoinduced new structure phase. We also found that nano-sheet samples with the thickness less than the optical penetration depth are required for attaining a complete transition.
Collapse
Affiliation(s)
- Q M Liu
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, China
| | - D Wu
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, China.
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, China.
| | - Z A Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - L Y Shi
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, China
| | - Z X Wang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, China
| | - S J Zhang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, China
| | - T Lin
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, China
| | - T C Hu
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, China
| | - H F Tian
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - J Q Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - T Dong
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, China
| | - N L Wang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing, China.
- Collaborative Innovation Center of Quantum Matter, Beijing, China.
| |
Collapse
|
186
|
Wang F, Pei K, Li Y, Li H, Zhai T. 2D Homojunctions for Electronics and Optoelectronics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2005303. [PMID: 33644885 DOI: 10.1002/adma.202005303] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 09/19/2020] [Indexed: 05/21/2023]
Abstract
In the post-Moore era, 2D materials with rich physical properties have attracted widespread attention from the scientific and industrial communities. Among 2D materials, the 2D homojunctions are of great promise in designing novel electronic and optoelectronic devices due to their unique geometries and properties such as homogeneous components, perfect lattice matching, and efficient charge transfer at the interface. In this article, a pioneering review focusing on the structural design and device application of 2D homojunctions such as p-n homojunctions, heterophase homojunctions, and layer-engineered homojunctions is provided. The preparation strategies to construct 2D homojunctions including vapor-phase deposition, lithium intercalation, laser irradiation, chemical doping, electrostatic doping, and photodoping are summarized in detail. Specifically, a careful review on the applications of the 2D homojunctions in electronics (e.g., field-effect transistors, rectifiers, and inverters) and optoelectronics (e.g., light-emitting diodes, photovoltaics, and photodetectors) is provided. Eventually, the current challenges and future perspectives are commented for promoting the rapid development of 2D homojunctions.
Collapse
Affiliation(s)
- Fakun Wang
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| | - Ke Pei
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| | - Yuan Li
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| | - Huiqiao Li
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| | - Tianyou Zhai
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
| |
Collapse
|
187
|
Pace S, Martini L, Convertino D, Keum DH, Forti S, Pezzini S, Fabbri F, Mišeikis V, Coletti C. Synthesis of Large-Scale Monolayer 1T'-MoTe 2 and Its Stabilization via Scalable hBN Encapsulation. ACS NANO 2021; 15:4213-4225. [PMID: 33605730 PMCID: PMC8023802 DOI: 10.1021/acsnano.0c05936] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 02/02/2021] [Indexed: 06/02/2023]
Abstract
Out of the different structural phases of molybdenum ditelluride (MoTe2), the distorted octahedral 1T' possesses great interest for fundamental physics and is a promising candidate for the implementation of innovative devices such as topological transistors. Indeed, 1T'-MoTe2 is a semimetal with superconductivity, which has been predicted to be a Weyl semimetal and a quantum spin Hall insulator in bulk and monolayer form, respectively. Large instability of monolayer 1T'-MoTe2 in environmental conditions, however, has made its investigation extremely challenging so far. In this work, we demonstrate homogeneous growth of large single-crystal (up to 500 μm) monolayer 1T'-MoTe2 via chemical vapor deposition (CVD) and its stabilization in air with a scalable encapsulation approach. The encapsulant is obtained by electrochemically delaminating CVD hexagonal boron nitride (hBN) from copper foil, and it is applied on the freshly grown 1T'-MoTe2 via a top-down dry lamination step. The structural and electrical properties of encapsulated 1T'-MoTe2 have been monitored over several months to assess the degree of degradation of the material. We find that when encapsulated with hBN, the lifetime of monolayer 1T'-MoTe2 successfully increases from a few minutes to more than a month. Furthermore, the encapsulated monolayer can be subjected to transfer, device processing, and heating and cooling cycles without degradation of its properties. The potential of this scalable heterostack is confirmed by the observation of signatures of low-temperature phase transition in monolayer 1T'-MoTe2 by both Raman spectroscopy and electrical measurements. The growth and encapsulation methods reported in this work can be employed for further fundamental studies of this enticing material as well as facilitate the technological development of monolayer 1T'-MoTe2.
Collapse
Affiliation(s)
- Simona Pace
- Center
for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa, Italy
- Graphene
Laboratories, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
| | - Leonardo Martini
- Center
for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa, Italy
| | - Domenica Convertino
- Center
for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa, Italy
- Graphene
Laboratories, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
| | - Dong Hoon Keum
- Center
for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa, Italy
- Graphene
Laboratories, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
| | - Stiven Forti
- Center
for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa, Italy
| | - Sergio Pezzini
- Center
for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa, Italy
- Graphene
Laboratories, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
| | - Filippo Fabbri
- Center
for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa, Italy
- Graphene
Laboratories, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
| | - Vaidotas Mišeikis
- Center
for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa, Italy
- Graphene
Laboratories, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
| | - Camilla Coletti
- Center
for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa, Italy
- Graphene
Laboratories, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
| |
Collapse
|
188
|
Jo K, Kumar P, Orr J, Anantharaman SB, Miao J, Motala MJ, Bandyopadhyay A, Kisslinger K, Muratore C, Shenoy VB, Stach EA, Glavin NR, Jariwala D. Direct Optoelectronic Imaging of 2D Semiconductor-3D Metal Buried Interfaces. ACS NANO 2021; 15:5618-5630. [PMID: 33683881 DOI: 10.1021/acsnano.1c00708] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The semiconductor-metal junction is one of the most critical factors for high-performance electronic devices. In two-dimensional (2D) semiconductor devices, minimizing the voltage drop at this junction is particularly challenging and important. Despite numerous studies concerning contact resistance in 2D semiconductors, the exact nature of the buried interface under a three-dimensional (3D) metal remains unclear. Herein, we report the direct measurement of electrical and optical responses of 2D semiconductor-metal buried interfaces using a recently developed metal-assisted transfer technique to expose the buried interface, which is then directly investigated using scanning probe techniques. We characterize the spatially varying electronic and optical properties of this buried interface with <20 nm resolution. To be specific, potential, conductance, and photoluminescence at the buried metal/MoS2 interface are correlated as a function of a variety of metal deposition conditions as well as the type of metal contacts. We observe that direct evaporation of Au on MoS2 induces a large strain of ∼5% in the MoS2 which, coupled with charge transfer, leads to degenerate doping of the MoS2 underneath the contact. These factors lead to improvement of contact resistance to record values of 138 kΩ μm, as measured using local conductance probes. This approach was adopted to characterize MoS2-In/Au alloy interfaces, demonstrating contact resistance as low as 63 kΩ μm. Our results highlight that the MoS2/metal interface is sensitive to device fabrication methods and provide a universal strategy to characterize buried contact interfaces involving 2D semiconductors.
Collapse
Affiliation(s)
- Kiyoung Jo
- Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Pawan Kumar
- Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Joseph Orr
- Electrical and Computer Engineering, Villanova University, Villanova, Pennsylvania 19085, United States
| | - Surendra B Anantharaman
- Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Jinshui Miao
- Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Michael J Motala
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson AFB, Ohio 45433, United States
- UES Inc., Beavercreek, Ohio 45432, United States
| | - Arkamita Bandyopadhyay
- Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Kim Kisslinger
- Brookhaven National Laboratory, Upton, New York 11973, United States
| | | | - Vivek B Shenoy
- Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Eric A Stach
- Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Nicholas R Glavin
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson AFB, Ohio 45433, United States
| | - Deep Jariwala
- Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| |
Collapse
|
189
|
Sun Y, Terrones M, Schaak RE. Colloidal Nanostructures of Transition-Metal Dichalcogenides. Acc Chem Res 2021; 54:1517-1527. [PMID: 33662209 DOI: 10.1021/acs.accounts.1c00006] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
ConspectusLayered transition-metal dichalcogenides (TMDs) are intriguing two-dimensional (2D) compounds where metal and chalcogen atoms are covalently bonded in each monolayer, and the monolayers are held together by weak van der Waals forces. Distinct from graphene, which is chemically inert, layered TMDs exhibit a wide range of electronic, optical, catalytic, and magnetic properties dependent upon their compositions, crystal structures, and thicknesses, which make them fundamentally and technologically important. TMD nanostructures are traditionally synthesized using gas-phase chemical deposition methods, which are typically limited to small-scale samples of substrate-bound planar materials. Colloidal synthesis has emerged as an alternative synthesis approach to enable the scalable synthesis of free-standing TMDs. The judicious selection of precursors, solvents, and capping ligands together with the optimization of synthesis parameters such as concentrations and temperatures leads to the fabrication of colloidal TMD nanostructures exhibiting tunable properties. In addition, understanding the formation and transformation of TMD nanostructures in solution contributes to the discovery of important structure-function relationships, which may be extendable to other anisotropic systems.In this Account, we summarize recent progress in the colloidal synthesis, characterization, and applications of TMD nanostructures with tunable compositions, structures, and thicknesses. On the basis of the preparation of Mo- and W-based disulfide, diselenide, and ditelluride nanostructures, we discuss examples of phase engineering where various metastable TMD compounds can be directly accessed at low temperatures in solution. We also analyze the chemistry involved in broadly tuning the composition across the MoSe2-WSe2, WS2-WSe2, and MoTe2-WTe2 solid solutions as well as atomic-level microscopic characterization and the resulting composition-tunable properties. We then highlight how the high densities of defects in the colloidally synthesized TMD nanostructures enable unique catalytic properties, including their ability to facilitate the selective hydrogenation of substituted nitroarenes using molecular hydrogen. Finally, using this library of colloidal TMD nanostructures as substrates, we discuss the pathways by which noble metals deposit onto them in solution. We highlight the importance of the relative strengths of the interfacial metal-chalcogen bonds in determining the sizes and morphologies of the deposited noble metal components. These synthesis capabilities for colloidal TMD nanostructures, which have been generalized to a library of composition-tunable phases, enable new systematic studies of structure-property relationships and chemical reactivity in this important class of 2D materials.
Collapse
|
190
|
Zhang X, Liu B, Gao L, Yu H, Liu X, Du J, Xiao J, Liu Y, Gu L, Liao Q, Kang Z, Zhang Z, Zhang Y. Near-ideal van der Waals rectifiers based on all-two-dimensional Schottky junctions. Nat Commun 2021; 12:1522. [PMID: 33750797 PMCID: PMC7943806 DOI: 10.1038/s41467-021-21861-6] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 02/17/2021] [Indexed: 01/31/2023] Open
Abstract
The applications of any two-dimensional (2D) semiconductor devices cannot bypass the control of metal-semiconductor interfaces, which can be severely affected by complex Fermi pinning effects and defect states. Here, we report a near-ideal rectifier in the all-2D Schottky junctions composed of the 2D metal 1 T'-MoTe2 and the semiconducting monolayer MoS2. We show that the van der Waals integration of the two 2D materials can efficiently address the severe Fermi pinning effect generated by conventional metals, leading to increased Schottky barrier height. Furthermore, by healing original atom-vacancies and reducing the intrinsic defect doping in MoS2, the Schottky barrier width can be effectively enlarged by 59%. The 1 T'-MoTe2/healed-MoS2 rectifier exhibits a near-unity ideality factor of ~1.6, a rectifying ratio of >5 × 105, and high external quantum efficiency exceeding 20%. Finally, we generalize the barrier optimization strategy to other Schottky junctions, defining an alternative solution to enhance the performance of 2D-material-based electronic devices.
Collapse
Affiliation(s)
- Xiankun Zhang
- Beijing Advanced Innovation Center for Materials Genome Engineering, Beijing Key Laboratory for Advanced Energy Materials and Technologies, University of Science and Technology Beijing, Beijing, People's Republic of China
- State Key Laboratory for Advanced Metals and Materials, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, People's Republic of China
| | - Baishan Liu
- Beijing Advanced Innovation Center for Materials Genome Engineering, Beijing Key Laboratory for Advanced Energy Materials and Technologies, University of Science and Technology Beijing, Beijing, People's Republic of China
| | - Li Gao
- Beijing Advanced Innovation Center for Materials Genome Engineering, Beijing Key Laboratory for Advanced Energy Materials and Technologies, University of Science and Technology Beijing, Beijing, People's Republic of China
| | - Huihui Yu
- Beijing Advanced Innovation Center for Materials Genome Engineering, Beijing Key Laboratory for Advanced Energy Materials and Technologies, University of Science and Technology Beijing, Beijing, People's Republic of China
| | - Xiaozhi Liu
- Collaborative Innovation Center of Quantum Matter, Beijing, China
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Junli Du
- Beijing Advanced Innovation Center for Materials Genome Engineering, Beijing Key Laboratory for Advanced Energy Materials and Technologies, University of Science and Technology Beijing, Beijing, People's Republic of China
| | - Jiankun Xiao
- Beijing Advanced Innovation Center for Materials Genome Engineering, Beijing Key Laboratory for Advanced Energy Materials and Technologies, University of Science and Technology Beijing, Beijing, People's Republic of China
| | - Yihe Liu
- Beijing Advanced Innovation Center for Materials Genome Engineering, Beijing Key Laboratory for Advanced Energy Materials and Technologies, University of Science and Technology Beijing, Beijing, People's Republic of China
| | - Lin Gu
- Collaborative Innovation Center of Quantum Matter, Beijing, China
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Qingliang Liao
- Beijing Advanced Innovation Center for Materials Genome Engineering, Beijing Key Laboratory for Advanced Energy Materials and Technologies, University of Science and Technology Beijing, Beijing, People's Republic of China
| | - Zhuo Kang
- Beijing Advanced Innovation Center for Materials Genome Engineering, Beijing Key Laboratory for Advanced Energy Materials and Technologies, University of Science and Technology Beijing, Beijing, People's Republic of China
| | - Zheng Zhang
- Beijing Advanced Innovation Center for Materials Genome Engineering, Beijing Key Laboratory for Advanced Energy Materials and Technologies, University of Science and Technology Beijing, Beijing, People's Republic of China.
- State Key Laboratory for Advanced Metals and Materials, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, People's Republic of China.
| | - Yue Zhang
- Beijing Advanced Innovation Center for Materials Genome Engineering, Beijing Key Laboratory for Advanced Energy Materials and Technologies, University of Science and Technology Beijing, Beijing, People's Republic of China.
- State Key Laboratory for Advanced Metals and Materials, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, People's Republic of China.
| |
Collapse
|
191
|
Stanley LJ, Chuang HJ, Zhou Z, Koehler MR, Yan J, Mandrus DG, Popović D. Low-Temperature 2D/2D Ohmic Contacts in WSe 2 Field-Effect Transistors as a Platform for the 2D Metal-Insulator Transition. ACS APPLIED MATERIALS & INTERFACES 2021; 13:10594-10602. [PMID: 33617715 DOI: 10.1021/acsami.0c21440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We report the fabrication of hexagonal-boron-nitride (hBN) encapsulated multiterminal WSe2 Hall bars with 2D/2D low-temperature Ohmic contacts as a platform for investigating the two-dimensional (2D) metal-insulator transition. We demonstrate that the WSe2 devices exhibit Ohmic behavior down to 0.25 K and at low enough excitation voltages to avoid current-heating effects. Additionally, the high-quality hBN-encapsulated WSe2 devices in ideal Hall-bar geometry enable us to accurately determine the carrier density. Measurements of the temperature (T) and density (ns) dependence of the conductivity σ(T, ns) demonstrate scaling behavior consistent with a metal-insulator quantum phase transition driven by electron-electron interactions but where disorder-induced local magnetic moments are also present. Our findings pave the way for further studies of the fundamental quantum mechanical properties of 2D transition metal dichalcogenides using the same contact engineering.
Collapse
Affiliation(s)
- Lily J Stanley
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
- Department of Physics, Florida State University, Tallahassee, Florida 32306, United States
| | - Hsun-Jen Chuang
- Physics and Astronomy Department, Wayne State University, Detroit, Michigan 48202, United States
| | - Zhixian Zhou
- Physics and Astronomy Department, Wayne State University, Detroit, Michigan 48202, United States
| | - Michael R Koehler
- Department of Materials Science and Engineering, The University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Jiaqiang Yan
- Department of Materials Science and Engineering, The University of Tennessee, Knoxville, Tennessee 37996, United States
- Oak Ridge National Lab, Oak Ridge, Tennessee 37830, United States
| | - David G Mandrus
- Department of Materials Science and Engineering, The University of Tennessee, Knoxville, Tennessee 37996, United States
- Oak Ridge National Lab, Oak Ridge, Tennessee 37830, United States
| | - Dragana Popović
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
- Department of Physics, Florida State University, Tallahassee, Florida 32306, United States
| |
Collapse
|
192
|
Promises and prospects of two-dimensional transistors. Nature 2021; 591:43-53. [PMID: 33658691 DOI: 10.1038/s41586-021-03339-z] [Citation(s) in RCA: 307] [Impact Index Per Article: 102.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Accepted: 12/14/2020] [Indexed: 01/31/2023]
Abstract
Two-dimensional (2D) semiconductors have attracted tremendous interest as atomically thin channels that could facilitate continued transistor scaling. However, despite many proof-of-concept demonstrations, the full potential of 2D transistors has yet to be determined. To this end, the fundamental merits and technological limits of 2D transistors need a critical assessment and objective projection. Here we review the promise and current status of 2D transistors, and emphasize that widely used device parameters (such as carrier mobility and contact resistance) could be frequently misestimated or misinterpreted, and may not be the most reliable performance metrics for benchmarking 2D transistors. We suggest that the saturation or on-state current density, especially in the short-channel limit, could provide a more reliable measure for assessing the potential of diverse 2D semiconductors, and should be applied for cross-checking different studies, especially when milestone performance metrics are claimed. We also summarize the key technical challenges in optimizing the channels, contacts, dielectrics and substrates and outline potential pathways to push the performance limit of 2D transistors. We conclude with an overview of the critical technical targets, the key technological obstacles to the 'lab-to-fab' transition and the potential opportunities arising from the use of these atomically thin semiconductors.
Collapse
|
193
|
Luo ZD, Yang MM, Liu Y, Alexe M. Emerging Opportunities for 2D Semiconductor/Ferroelectric Transistor-Structure Devices. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2005620. [PMID: 33577112 DOI: 10.1002/adma.202005620] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 09/26/2020] [Indexed: 06/12/2023]
Abstract
Semiconductor technology, which is rapidly evolving, is poised to enter a new era for which revolutionary innovations are needed to address fundamental limitations on material and working principle level. 2D semiconductors inherently holding novel properties at the atomic limit show great promise to tackle challenges imposed by traditional bulk semiconductor materials. Synergistic combination of 2D semiconductors with functional ferroelectrics further offers new working principles, and is expected to deliver massively enhanced device performance for existing complementary metal-oxide-semiconductor (CMOS) technologies and add unprecedented applications for next-generation electronics. Herein, recent demonstrations of novel device concepts based on 2D semiconductor/ferroelectric heterostructures are critically reviewed covering their working mechanisms, device construction, applications, and challenges. In particular, emerging opportunities of CMOS-process-compatible 2D semiconductor/ferroelectric transistor structure devices for the development of a rich variety of applications are discussed, including beyond-Boltzmann transistors, nonvolatile memories, neuromorphic devices, and reconfigurable nanodevices such as p-n homojunctions and self-powered photodetectors. It is concluded that 2D semiconductor/ferroelectric heterostructures, as an emergent heterogeneous platform, could drive many more exciting innovations for modern electronics, beyond the capability of ubiquitous silicon systems.
Collapse
Affiliation(s)
- Zheng-Dong Luo
- Department of Physics, The University of Warwick, Coventry, CV4 7AL, UK
| | - Ming-Min Yang
- Center for Emergent Matter Science, RIKEN, Wako, Saitama, 351-0198, Japan
| | - Yang Liu
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Marin Alexe
- Department of Physics, The University of Warwick, Coventry, CV4 7AL, UK
| |
Collapse
|
194
|
Jang M, Bae H, Lee Y, Na W, Yu B, Choi S, Cheong H, Lee H, Kim K. Unidirectional Alignment of AgCN Microwires on Distorted Transition Metal Dichalcogenide Crystals. ACS APPLIED MATERIALS & INTERFACES 2021; 13:8727-8735. [PMID: 33561342 DOI: 10.1021/acsami.0c20246] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Van der Waals epitaxy on the surface of two-dimensional (2D) layered crystals has gained significant research interest for the assembly of well-ordered nanostructures and fabrication of vertical heterostructures based on 2D crystals. Although van der Waals epitaxial assembly on the hexagonal phase of transition metal dichalcogenides (TMDCs) has been relatively well characterized, a comparable study on the distorted octahedral phase (1T' or Td) of TMDCs is largely lacking. Here, we investigate the assembly behavior of one-dimensional (1D) AgCN microwires on various distorted TMDC crystals, namely 1T'-MoTe2, Td-WTe2, and 1T'-ReS2. The unidirectional alignment of AgCN chains is observed on these crystals, reflecting the symmetry of underlying distorted TMDCs. Polarized Raman spectroscopy and transmission electron microscopy directly confirm that AgCN chains display the remarkable alignment behavior along the distorted chain directions of underlying TMDCs. The observed unidirectional assembly behavior can be attributed to the favorable adsorption configurations of 1D chains along the substrate distortion, which is supported by our theoretical calculations and observation of similar assembly behavior from different cyanide chains. The aligned AgCN microwires can be harnessed as facile markers to identify polymorphs and crystal orientations of TMDCs.
Collapse
Affiliation(s)
- Myeongjin Jang
- Department of Physics, Yonsei University, Seoul 03722, Korea
- Center for Nanomedicine, Institute for Basic Science (IBS), Seoul 03722, Korea
| | - Hyeonhu Bae
- Department of Physics, Konkuk University, Seoul 05029, Korea
| | - Yangjin Lee
- Department of Physics, Yonsei University, Seoul 03722, Korea
- Center for Nanomedicine, Institute for Basic Science (IBS), Seoul 03722, Korea
| | - Woongki Na
- Department of Physics, Sogang University, Seoul 04107, Korea
| | - Byungkyu Yu
- Center for Nanomedicine, Institute for Basic Science (IBS), Seoul 03722, Korea
| | - Soyeon Choi
- Department of Physics, Yonsei University, Seoul 03722, Korea
| | - Hyeonsik Cheong
- Department of Physics, Sogang University, Seoul 04107, Korea
| | - Hoonkyung Lee
- Department of Physics, Konkuk University, Seoul 05029, Korea
| | - Kwanpyo Kim
- Department of Physics, Yonsei University, Seoul 03722, Korea
- Center for Nanomedicine, Institute for Basic Science (IBS), Seoul 03722, Korea
| |
Collapse
|
195
|
Feng J, Gao H, Li T, Tan X, Xu P, Li M, He L, Ma D. Lattice-Matched Metal-Semiconductor Heterointerface in Monolayer Cu 2Te. ACS NANO 2021; 15:3415-3422. [PMID: 33496565 DOI: 10.1021/acsnano.0c10442] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The interface between metals and semiconductors plays an essential role in two-dimensional electronic heterostructures, which has provided an alternative opportunity to realize next-generation electronic devices. Lattice-matched two-dimensional heterointerfaces have been achieved in polymorphic 2D transition-metal dichalcogenides MX2 with M = (W, Mo) and X = (Te, Se, S) through phase engineering; yet other transition-metal chalcogenides have been rarely reported. Here we show that a single layer of hexagonal Cu2Te crystal could be synthesized by one-step liquid-solid interface growth and exfoliation. Characterizations of atomically resolved scanning tunneling microscope reveal that the Cu2Te monolayer consists of two lattice-matched distinct phases, similar to the 1T and 1T' phases of MX2. The scanning tunneling spectra identify the coexistence of the metallic 1T and semiconducting 1T' phases within the chemically homogeneous Cu2Te crystals, as confirmed by density functional theory calculations. Moreover, the two phases could form nanoscale lattice-matched metal-semiconductor junctions with atomically sharp interfaces. These results suggest a promising potential for exploiting atomic-scale electronic devices in 2D materials.
Collapse
Affiliation(s)
- Jingqi Feng
- Department of Physics, Capital Normal University, Beijing 100048, People's Republic of China
| | - Huiying Gao
- Department of Physics, Capital Normal University, Beijing 100048, People's Republic of China
| | - Tian Li
- Department of Physics, Capital Normal University, Beijing 100048, People's Republic of China
| | - Xin Tan
- Department of Physics, Capital Normal University, Beijing 100048, People's Republic of China
| | - Peng Xu
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, People's Republic of China
| | - Menglei Li
- Department of Physics, Capital Normal University, Beijing 100048, People's Republic of China
| | - Lin He
- Department of Physics, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Donglin Ma
- Department of Physics, Capital Normal University, Beijing 100048, People's Republic of China
| |
Collapse
|
196
|
Liang Q, Zhang Q, Zhao X, Liu M, Wee ATS. Defect Engineering of Two-Dimensional Transition-Metal Dichalcogenides: Applications, Challenges, and Opportunities. ACS NANO 2021; 15:2165-2181. [PMID: 33449623 DOI: 10.1021/acsnano.0c09666] [Citation(s) in RCA: 97] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Atomic defects, being the most prevalent zero-dimensional topological defects, are ubiquitous in a wide range of 2D transition-metal dichalcogenides (TMDs). They could be intrinsic, formed during the initial sample growth, or created by postprocessing. Despite the majority of TMDs being largely unaffected after losing chalcogen atoms in the outermost layer, a spectrum of properties, including optical, electrical, and chemical properties, can be significantly modulated, and potentially invoke applicable functionalities utilized in many applications. Hence, controlling chalcogen atomic defects provides an alternative avenue for engineering a wide range of physical and chemical properties of 2D TMDs. In this article, we review recent progress on the role of chalcogen atomic defects in engineering 2D TMDs, with a particular focus on device performance improvements. Various approaches for creating chalcogen atomic defects including nonstoichiometric synthesis and postgrowth treatment, together with their characterization and interpretation are systematically overviewed. The tailoring of optical, electrical, and magnetic properties, along with the device performance enhancement in electronic, optoelectronic, chemical sensing, biomedical, and catalytic activity are discussed in detail. Postformation dynamic evolution and repair of chalcogen atomic defects are also introduced. Finally, we offer our perspective on the challenges and opportunities in this field.
Collapse
Affiliation(s)
- Qijie Liang
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117551, Singapore
| | - Qian Zhang
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117575, Singapore
| | - Xiaoxu Zhao
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117575, Singapore
| | - Meizhuang Liu
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117551, Singapore
| | - Andrew T S Wee
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117551, Singapore
- Centre for Advanced 2D Materials, National University of Singapore, 6 Science Drive 2, Singapore 117546, Singapore
| |
Collapse
|
197
|
Cheon Y, Lim SY, Kim K, Cheong H. Structural Phase Transition and Interlayer Coupling in Few-Layer 1T' and T d MoTe 2. ACS NANO 2021; 15:2962-2970. [PMID: 33480685 DOI: 10.1021/acsnano.0c09162] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We performed polarized Raman spectroscopy on mechanically exfoliated few-layer MoTe2 samples and observed both 1T' and Td phases at room temperature. Few-layer 1T' and Td MoTe2 exhibited a significant difference especially in interlayer vibration modes, from which the interlayer coupling strengths were extracted using the linear chain model: strong in-plane anisotropy was observed in both phases. Furthermore, temperature-dependent Raman measurements revealed a peculiar phase transition behavior in few-layer 1T' MoTe2. In contrast to bulk 1T' MoTe2 crystals, where the phase transition to the Td phase occurs at ∼250 K, the temperature-driven phase transition to the Td phase is increasingly suppressed as the thickness is reduced, and the transition and the critical temperature varied dramatically from sample to sample even for the same thickness. Raman spectra of intermediate phases that correspond to neither 1T' nor Td phase with different interlayer vibration modes were observed, which suggests that several metastable phases exist with similar total energies.
Collapse
Affiliation(s)
- Yeryun Cheon
- Department of Physics, Sogang University, Seoul 04107, Korea
| | - Soo Yeon Lim
- Department of Physics, Sogang University, Seoul 04107, Korea
| | - Kangwon Kim
- Department of Physics, Sogang University, Seoul 04107, Korea
| | - Hyeonsik Cheong
- Department of Physics, Sogang University, Seoul 04107, Korea
| |
Collapse
|
198
|
Lim J, Kadyrov A, Jeon D, Choi Y, Bae J, Lee S. Contact Engineering of Vertically Grown ReS 2 with Schottky Barrier Modulation. ACS APPLIED MATERIALS & INTERFACES 2021; 13:7529-7538. [PMID: 33544572 DOI: 10.1021/acsami.0c20108] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Forming metal contact with low contact resistance is essential for the development of electronics based on layered van der Waals materials. ReS2 is a semiconducting transition metal dichalcogenide (TMD) with an MX2 structure similar to that of MoS2. While most TMDs grow parallel to the substrate when synthesized using chemical vapor deposition (CVD), ReS2 tends to orient itself vertically during growth. Such a feature drastically increases the surface area and exposes chemically active edges, making ReS2 an attractive layered material for energy and sensor applications. However, the contact resistances of vertically grown materials are known to be relatively high, compared to those of common 2H-phase TMDs, such as MoS2. Most reported methods for lowering the contact resistance have been focused on exfoliated 2H-phase materials with only a few devices tested, and few works on distorted T-phase materials exist. Moreover, nearly all reported studies have been conducted on only a few devices with mechanically exfoliated fl Most reported methods for lowering the contact resistance have been 2 contacts was modulated by conformally coating a thin tunneling interlayer between the metal and the dendritic ReS2 film. Over a hundred devices were tested, and contact resistances were extracted for large-scale statistical analysis. Importantly, we compared various known materials and techniques for lowering contact resistance and found an optimized method. Finally, the reductions in barrier height were directly correlated with exponential reductions in contact resistance and increases in drive-current by almost 2 orders of magnitude.
Collapse
Affiliation(s)
- Jinho Lim
- Semiconductor Device & Integration Laboratory, Department of Electronic Engineering, Kyunghee University, Yongin 17104, Korea
| | - Arman Kadyrov
- Semiconductor Device & Integration Laboratory, Department of Electronic Engineering, Kyunghee University, Yongin 17104, Korea
| | - Dasom Jeon
- Semiconductor Device & Integration Laboratory, Department of Electronic Engineering, Kyunghee University, Yongin 17104, Korea
| | - Yongsu Choi
- Semiconductor Device & Integration Laboratory, Department of Electronic Engineering, Kyunghee University, Yongin 17104, Korea
| | - Junho Bae
- Semiconductor Device & Integration Laboratory, Department of Electronic Engineering, Kyunghee University, Yongin 17104, Korea
| | - Seunghyun Lee
- Semiconductor Device & Integration Laboratory, Department of Electronic Engineering, Kyunghee University, Yongin 17104, Korea
| |
Collapse
|
199
|
Lee JH, Shin DH, Yang H, Jeong NB, Park DH, Watanabe K, Taniguchi T, Kim E, Lee SW, Jhang SH, Park BH, Kuk Y, Chung HJ. Semiconductor-less vertical transistor with I ON/I OFF of 10 6. Nat Commun 2021; 12:1000. [PMID: 33579924 PMCID: PMC7881104 DOI: 10.1038/s41467-021-21138-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 01/11/2021] [Indexed: 01/30/2023] Open
Abstract
Semiconductors have long been perceived as a prerequisite for solid-state transistors. Although switching principles for nanometer-scale devices have emerged based on the deployment of two-dimensional (2D) van der Waals heterostructures, tunneling and ballistic currents through short channels are difficult to control, and semiconducting channel materials remain indispensable for practical switching. In this study, we report a semiconductor-less solid-state electronic device that exhibits an industry-applicable switching of the ballistic current. This device modulates the field emission barrier height across the graphene-hexagonal boron nitride interface with ION/IOFF of 106 obtained from the transfer curves and adjustable intrinsic gain up to 4, and exhibits unprecedented current stability in temperature range of 15-400 K. The vertical device operation can be optimized with the capacitive coupling in the device geometry. The semiconductor-less switching resolves the long-standing issue of temperature-dependent device performance, thereby extending the potential of 2D van der Waals devices to applications in extreme environments.
Collapse
Affiliation(s)
- Jun-Ho Lee
- grid.258676.80000 0004 0532 8339Department of Physics, Konkuk University, Seoul, Republic of Korea
| | - Dong Hoon Shin
- grid.255649.90000 0001 2171 7754Department of Physics, Ewha Womans University, Seoul, Republic of Korea
| | - Heejun Yang
- grid.37172.300000 0001 2292 0500Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon, 34141 Republic of Korea
| | - Nae Bong Jeong
- grid.258676.80000 0004 0532 8339Department of Physics, Konkuk University, Seoul, Republic of Korea
| | - Do-Hyun Park
- grid.258676.80000 0004 0532 8339Department of Physics, Konkuk University, Seoul, Republic of Korea
| | - Kenji Watanabe
- grid.21941.3f0000 0001 0789 6880Research Center for Functional Materials, National Institute for Materials Science, Tuskuba, Japan
| | - Takashi Taniguchi
- grid.21941.3f0000 0001 0789 6880International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tuskuba, Japan
| | - Eunah Kim
- grid.264381.a0000 0001 2181 989XDepartment of Energy Science, Sungkyunkwan University, Suwon, Republic of Korea
| | - Sang Wook Lee
- grid.255649.90000 0001 2171 7754Department of Physics, Ewha Womans University, Seoul, Republic of Korea
| | - Sung Ho Jhang
- grid.258676.80000 0004 0532 8339Department of Physics, Konkuk University, Seoul, Republic of Korea
| | - Bae Ho Park
- grid.258676.80000 0004 0532 8339Department of Physics, Konkuk University, Seoul, Republic of Korea
| | - Young Kuk
- grid.417736.00000 0004 0438 6721Daegu Gyeongbuk Institute of Science & Technology, Daegu, Republic of Korea
| | - Hyun-Jong Chung
- grid.258676.80000 0004 0532 8339Department of Physics, Konkuk University, Seoul, Republic of Korea
| |
Collapse
|
200
|
Bergeron H, Lebedev D, Hersam MC. Polymorphism in Post-Dichalcogenide Two-Dimensional Materials. Chem Rev 2021; 121:2713-2775. [PMID: 33555868 DOI: 10.1021/acs.chemrev.0c00933] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Two-dimensional (2D) materials exhibit a wide range of atomic structures, compositions, and associated versatility of properties. Furthermore, for a given composition, a variety of different crystal structures (i.e., polymorphs) can be observed. Polymorphism in 2D materials presents a fertile landscape for designing novel architectures and imparting new functionalities. The objective of this Review is to identify the polymorphs of emerging 2D materials, describe their polymorph-dependent properties, and outline methods used for polymorph control. Since traditional 2D materials (e.g., graphene, hexagonal boron nitride, and transition metal dichalcogenides) have already been studied extensively, the focus here is on polymorphism in post-dichalcogenide 2D materials including group III, IV, and V elemental 2D materials, layered group III, IV, and V metal chalcogenides, and 2D transition metal halides. In addition to providing a comprehensive survey of recent experimental and theoretical literature, this Review identifies the most promising opportunities for future research including how 2D polymorph engineering can provide a pathway to materials by design.
Collapse
Affiliation(s)
- Hadallia Bergeron
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Dmitry Lebedev
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Mark C Hersam
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States.,Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States.,Department of Electrical and Computer Engineering, Northwestern University, Evanston, Illinois 60208, United States
| |
Collapse
|