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Kang Y, Pei Y, He D, Xu H, Ma M, Yan J, Jiang C, Li W, Xiao X. Spatially selective p-type doping for constructing lateral WS 2 p-n homojunction via low-energy nitrogen ion implantation. LIGHT, SCIENCE & APPLICATIONS 2024; 13:127. [PMID: 38821920 PMCID: PMC11143290 DOI: 10.1038/s41377-024-01477-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 04/13/2024] [Accepted: 05/10/2024] [Indexed: 06/02/2024]
Abstract
The construction of lateral p-n junctions is very important and challenging in two-dimensional (2D) semiconductor manufacturing process. Previous researches have demonstrated that vertical p-n junction can be prepared simply by vertical stacking of 2D materials. However, interface pollution and large area scalability are challenges that are difficult to overcome with vertical stacking technology. Constructing 2D lateral p-n homojunction is an effective strategy to address these issues. Spatially selective p-type doping of 2D semiconductors is expected to construct lateral p-n homojunction. In this work, we have developed a low-energy ion implantation system that reduces the implanted energy to 300 eV. Low-energy implantation can form a shallow implantation depth, which is more suitable for modulating the electrical and optical properties of 2D materials. Hence, we utilize low-energy ion implantation to directly dope nitrogen ions into few-layer WS2 and successfully realize a precise regulation for WS2 with its conductivity type transforming from n-type to bipolar or even p-type conduction. Furthermore, the universality of this method is demonstrated by extending it to other 2D semiconductors, including WSe2, SnS2 and MoS2. Based on this method, a lateral WS2 p-n homojunction is fabricated, which exhibits significant rectification characteristics. A photodetector based on p-n junction with photovoltaic effect is also prepared, and the open circuit voltage can reach to 0.39 V. This work provides an effective way for controllable doping of 2D semiconductors.
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Affiliation(s)
- Yufan Kang
- School of Physics and Technology, Key Lab of Artificial Micro- and Nano-Structures of Ministry of Education, Wuhan University, Wuhan, China
| | - Yongfeng Pei
- School of Physics and Technology, Key Lab of Artificial Micro- and Nano-Structures of Ministry of Education, Wuhan University, Wuhan, China
| | - Dong He
- School of Physics and Technology, Key Lab of Artificial Micro- and Nano-Structures of Ministry of Education, Wuhan University, Wuhan, China
| | - Hang Xu
- School of Physics and Technology, Key Lab of Artificial Micro- and Nano-Structures of Ministry of Education, Wuhan University, Wuhan, China
| | - Mingjun Ma
- School of Physics and Technology, Key Lab of Artificial Micro- and Nano-Structures of Ministry of Education, Wuhan University, Wuhan, China
| | - Jialu Yan
- School of Physics and Technology, Key Lab of Artificial Micro- and Nano-Structures of Ministry of Education, Wuhan University, Wuhan, China
| | - Changzhong Jiang
- School of Physics and Technology, Key Lab of Artificial Micro- and Nano-Structures of Ministry of Education, Wuhan University, Wuhan, China
| | - Wenqing Li
- School of Physics and Technology, Key Lab of Artificial Micro- and Nano-Structures of Ministry of Education, Wuhan University, Wuhan, China.
| | - Xiangheng Xiao
- School of Physics and Technology, Key Lab of Artificial Micro- and Nano-Structures of Ministry of Education, Wuhan University, Wuhan, China.
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2
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Wang X, Chen A, Wu X, Zhang J, Dong J, Zhang L. Synthesis and Modulation of Low-Dimensional Transition Metal Chalcogenide Materials via Atomic Substitution. NANO-MICRO LETTERS 2024; 16:163. [PMID: 38546814 PMCID: PMC10978568 DOI: 10.1007/s40820-024-01378-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 02/17/2024] [Indexed: 04/01/2024]
Abstract
In recent years, low-dimensional transition metal chalcogenide (TMC) materials have garnered growing research attention due to their superior electronic, optical, and catalytic properties compared to their bulk counterparts. The controllable synthesis and manipulation of these materials are crucial for tailoring their properties and unlocking their full potential in various applications. In this context, the atomic substitution method has emerged as a favorable approach. It involves the replacement of specific atoms within TMC structures with other elements and possesses the capability to regulate the compositions finely, crystal structures, and inherent properties of the resulting materials. In this review, we present a comprehensive overview on various strategies of atomic substitution employed in the synthesis of zero-dimensional, one-dimensional and two-dimensional TMC materials. The effects of substituting elements, substitution ratios, and substitution positions on the structures and morphologies of resulting material are discussed. The enhanced electrocatalytic performance and photovoltaic properties of the obtained materials are also provided, emphasizing the role of atomic substitution in achieving these advancements. Finally, challenges and future prospects in the field of atomic substitution for fabricating low-dimensional TMC materials are summarized.
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Affiliation(s)
- Xuan Wang
- Key Laboratory of Cluster Science, Ministry of Education of China, Beijing Key Laboratory of Photoelectronic and Electrophonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, People's Republic of China
| | - Akang Chen
- Key Laboratory of Cluster Science, Ministry of Education of China, Beijing Key Laboratory of Photoelectronic and Electrophonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, People's Republic of China
| | - XinLei Wu
- Key Laboratory of Cluster Science, Ministry of Education of China, Beijing Key Laboratory of Photoelectronic and Electrophonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, People's Republic of China
| | - Jiatao Zhang
- Key Laboratory of Cluster Science, Ministry of Education of China, Beijing Key Laboratory of Photoelectronic and Electrophonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, People's Republic of China.
| | - Jichen Dong
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Organic Solids, Institute of Chemistry Chinese Academy of Sciences, Beijing, 100190, People's Republic of China.
| | - Leining Zhang
- Key Laboratory of Cluster Science, Ministry of Education of China, Beijing Key Laboratory of Photoelectronic and Electrophonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, People's Republic of China.
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3
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Zhou H, Liang K, Bi L, Shi Y, Wang Z, Li S. Spotlight: Visualization of Moiré Quantum Phenomena in Transition Metal Dichalcogenide with Scanning Tunneling Microscopy. ACS APPLIED ELECTRONIC MATERIALS 2024; 6:1530-1541. [PMID: 38558951 PMCID: PMC10976882 DOI: 10.1021/acsaelm.3c01328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 01/09/2024] [Accepted: 01/10/2024] [Indexed: 04/04/2024]
Abstract
Transition metal dichalcogenide (TMD) moiré superlattices have emerged as a significant area of study in condensed matter physics. Thanks to their superior optical properties, tunable electronic band structure, strong Coulomb interactions, and quenched electron kinetic energy, they offer exciting avenues to explore correlated quantum phenomena, topological properties, and light-matter interactions. In recent years, scanning tunneling microscopy (STM) has made significant impacts on the study of these fields by enabling intrinsic surface visualization and spectroscopic measurements with unprecedented atomic scale detail. Here, we spotlight the key findings and innovative developments in imaging and characterization of TMD heterostructures via STM, from its initial implementation on the in situ grown sample to the latest photocurrent tunneling microscopy. The evolution in sample design, progressing from a conductive to an insulating substrate, has not only expanded our control over TMD moiré superlattices but also promoted an understanding of their structures and strongly correlated properties, such as the structural reconstruction and formation of generalized two-dimensional Wigner crystal states. In addition to highlighting recent advancements, we outline upcoming challenges, suggest the direction of future research, and advocate for the versatile use of STM to further comprehend and manipulate the quantum dynamics in TMD moiré superlattices.
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Affiliation(s)
- Hao Zhou
- Department
of Chemistry and Biochemistry, University
of California, San Diego, La Jolla, California 92093-0309, United States
- Program
in Materials Science and Engineering, University
of California, San Diego, La Jolla, California 92093-0418, United States
| | - Kangkai Liang
- Department
of Chemistry and Biochemistry, University
of California, San Diego, La Jolla, California 92093-0309, United States
- Program
in Materials Science and Engineering, University
of California, San Diego, La Jolla, California 92093-0418, United States
| | - Liya Bi
- Department
of Chemistry and Biochemistry, University
of California, San Diego, La Jolla, California 92093-0309, United States
- Program
in Materials Science and Engineering, University
of California, San Diego, La Jolla, California 92093-0418, United States
| | - Yueqing Shi
- Department
of Chemistry and Biochemistry, University
of California, San Diego, La Jolla, California 92093-0309, United States
| | - Zihao Wang
- Department
of Chemistry and Biochemistry, University
of California, San Diego, La Jolla, California 92093-0309, United States
- School
of Physics, Nankai University, Tianjin 300071, China
| | - Shaowei Li
- Department
of Chemistry and Biochemistry, University
of California, San Diego, La Jolla, California 92093-0309, United States
- Program
in Materials Science and Engineering, University
of California, San Diego, La Jolla, California 92093-0418, United States
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4
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Kwon G, Kim HS, Jeong K, Kim M, Nam GH, Park H, Yoo K, Cho MH. Forming Stable van der Waals Contacts between Metals and 2D Semiconductors. SMALL METHODS 2023; 7:e2300376. [PMID: 37291738 DOI: 10.1002/smtd.202300376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 05/19/2023] [Indexed: 06/10/2023]
Abstract
High-performing 2D electrical and optical devices can be realized by forming an ideal van der Waals (vdW) metal contact with weak interactions and stable interface states. However, the methods for applying metal contacts while avoiding damage from metal deposition present challenges in realizing a uniform, stable vdW interface. To overcome this problem, this study develops a method for forming vdW contacts using a sacrificial Se buffer layer. This study explores this method by investigating the difference in the Schottky barrier height between the vdW metal contact deposited using a buffer layer, a transferred metal contact, and a conventional directly deposited metal contact using rectification and photovoltaic characteristics of a Schottky diode structure with graphite. Evidently, the Se buffer layer method forms the most stable and ideal vdW contact while preventing Fermi-level pinning. A tungsten diselenide Schottky diode fabricated using these vdW contacts with Au and graphite as the top and bottom electrodes, respectively, exhibits excellent operation with an ideality factor of ≈1, an on/off ratio of > 107 , and coherent properties. Additionally, when using only the vdW Au contact, the electrical and optical properties of the device can be minutely modulated by changing the structure of the Schottky diode.
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Affiliation(s)
- Gihyeon Kwon
- Department of Physics, Yonsei University, Seoul, 03722, Republic of Korea
| | - Hyeon-Sik Kim
- Department of Physics, Yonsei University, Seoul, 03722, Republic of Korea
| | - Kwangsik Jeong
- Division of Physics and Semiconductor Science, Dongguk University, Seoul, 04620, Republic of Korea
| | - Myeongjin Kim
- Department of Physics, Yonsei University, Seoul, 03722, Republic of Korea
| | - Gi Hwan Nam
- Department of Physics, Yonsei University, Seoul, 03722, Republic of Korea
| | - Hyunjun Park
- Department of Physics, Yonsei University, Seoul, 03722, Republic of Korea
| | - Kyunghwa Yoo
- Department of Physics, Yonsei University, Seoul, 03722, Republic of Korea
| | - Mann-Ho Cho
- Department of Physics, Yonsei University, Seoul, 03722, Republic of Korea
- Department of System Semiconductor Engineering, Yonsei University, Seoul, 03722, Republic of Korea
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5
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Lin YC, Chang YP, Chen KW, Lee TT, Hsiao BJ, Tsai TH, Yang YC, Lin KI, Suenaga K, Chen CH, Chiu PW. Patterning and doping of transition metals in tungsten dichalcogenides. NANOSCALE 2022; 14:16968-16977. [PMID: 36350092 DOI: 10.1039/d2nr04677f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Substitutional transition metal doping in two-dimensional (2D) layered dichalcogenides is of fundamental importance in manipulating their electrical, excitonic, magnetic, and catalytic properties through the variation of the d-electron population. Yet, most doping strategies are spatially global, with dopants embedded concurrently during the synthesis. Here, we report an area-selective doping scheme for W-based dichalcogenide single layers, in which pre-patterned graphene is used as a reaction mask in the high-temperature substitution of the W sublattice. The chemical inertness of the thin graphene layer can effectively differentiate the spatial doping reaction, allowing for local manipulation of the host 2D materials. Using graphene as a mask is also beneficial in the sense that it also acts as an insertion layer between the contact metal and the doped channel, capable of depinning the Fermi level for low contact resistivity. Tracing doping by means of chalcogen labelling, deliberate Cr embedment is found to become energetically favorable in the presence of chalcogen deficiency, assisting the substitution of the W sublattice in the devised chemical vapor doping scheme. Atomic characterization using scanning transmission electron microscopy (STEM) shows that the dopant concentration is controllable and varies linearly with the reaction time in the current doping approach. Using the same method, other transition metal atoms such as Mo, V, and Fe can also be doped in the patterned area.
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Affiliation(s)
- Yung-Chang Lin
- Nanomaterials Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8565, Japan
| | - Yao-Pang Chang
- Department of Electrical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan.
| | - Kai-Wen Chen
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - Tai-Ting Lee
- Department of Electrical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan.
| | - Bo-Jiun Hsiao
- Department of Electrical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan.
| | - Tsung-Han Tsai
- Department of Electrical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan.
| | - Yueh-Chiang Yang
- Department of Electrical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan.
| | - Kuang-I Lin
- Center for Micro/Nano Science and Technology, National Cheng Kung University, Tainan 70101, Taiwan
| | - Kazu Suenaga
- Nanomaterials Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8565, Japan
- The Institute of Scientific and Industrial Research (ISIR-SANKEN), Osaka University, Osaka 567-0047, Japan
| | - Chia-Hao Chen
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
- Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan
| | - Po-Wen Chiu
- Department of Electrical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan.
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
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6
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Kirubasankar B, Won YS, Adofo LA, Choi SH, Kim SM, Kim KK. Atomic and structural modifications of two-dimensional transition metal dichalcogenides for various advanced applications. Chem Sci 2022; 13:7707-7738. [PMID: 35865881 PMCID: PMC9258346 DOI: 10.1039/d2sc01398c] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 05/18/2022] [Indexed: 12/14/2022] Open
Abstract
Two-dimensional (2D) transition metal dichalcogenides (TMDs) and their heterostructures have attracted significant interest in both academia and industry because of their unusual physical and chemical properties. They offer numerous applications, such as electronic, optoelectronic, and spintronic devices, in addition to energy storage and conversion. Atomic and structural modifications of van der Waals layered materials are required to achieve unique and versatile properties for advanced applications. This review presents a discussion on the atomic-scale and structural modifications of 2D TMDs and their heterostructures via post-treatment. Atomic-scale modifications such as vacancy generation, substitutional doping, functionalization and repair of 2D TMDs and structural modifications including phase transitions and construction of heterostructures are discussed. Such modifications on the physical and chemical properties of 2D TMDs enable the development of various advanced applications including electronic and optoelectronic devices, sensing, catalysis, nanogenerators, and memory and neuromorphic devices. Finally, the challenges and prospects of various post-treatment techniques and related future advanced applications are addressed.
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Affiliation(s)
- Balakrishnan Kirubasankar
- Department of Energy Science, Sungkyunkwan University Suwon 16419 South Korea
- Department of Chemistry, Sookmyung Women's University Seoul 14072 South Korea
| | - Yo Seob Won
- Department of Energy Science, Sungkyunkwan University Suwon 16419 South Korea
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Sungkyunkwan University Suwon 16419 South Korea
| | - Laud Anim Adofo
- Department of Energy Science, Sungkyunkwan University Suwon 16419 South Korea
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Sungkyunkwan University Suwon 16419 South Korea
| | - Soo Ho Choi
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Sungkyunkwan University Suwon 16419 South Korea
| | - Soo Min Kim
- Department of Chemistry, Sookmyung Women's University Seoul 14072 South Korea
| | - Ki Kang Kim
- Department of Energy Science, Sungkyunkwan University Suwon 16419 South Korea
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Sungkyunkwan University Suwon 16419 South Korea
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7
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Yao J, Yang G. 2D Layered Material Alloys: Synthesis and Application in Electronic and Optoelectronic Devices. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2103036. [PMID: 34719873 PMCID: PMC8728821 DOI: 10.1002/advs.202103036] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 09/01/2021] [Indexed: 05/12/2023]
Abstract
2D layered materials (2DLMs) have come under the limelight of scientific and engineering research and broke new ground across a broad range of disciplines in the past decade. Nevertheless, the members of stoichiometric 2DLMs are relatively limited. This renders them incompetent to fulfill the multitudinous scenarios across the breadth of electronic and optoelectronic applications since the characteristics exhibited by a specific material are relatively monotonous and limited. Inspiringly, alloying of 2DLMs can markedly broaden the 2D family through composition modulation and it has ushered a whole new research domain: 2DLM alloy nano-electronics and nano-optoelectronics. This review begins with a comprehensive survey on synthetic technologies for the production of 2DLM alloys, which include chemical vapor transport, chemical vapor deposition, pulsed-laser deposition, and molecular beam epitaxy, spanning their development, as well as, advantages and disadvantages. Then, the up-to-date advances of 2DLM alloys in electronic devices are summarized. Subsequently, the up-to-date advances of 2DLM alloys in optoelectronic devices are summarized. In the end, the ongoing challenges of this emerging field are highlighted and the future opportunities are envisioned, which aim to navigate the coming exploration and fully exert the pivotal role of 2DLMs toward the next generation of electronic and optoelectronic devices.
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Affiliation(s)
- Jiandong Yao
- State Key Laboratory of Optoelectronic Materials and Technologies, Nanotechnology Research Center, School of Materials Science & Engineering, Sun Yat-sen University, Guangzhou, Guangdong, 510275, P. R. China
| | - Guowei Yang
- State Key Laboratory of Optoelectronic Materials and Technologies, Nanotechnology Research Center, School of Materials Science & Engineering, Sun Yat-sen University, Guangzhou, Guangdong, 510275, P. R. China
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8
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Influence of Cu Irons on Structural, Optical, and Electrical Properties of Pure WS2 Thin Films and Development of p-Si/n-Cu@WS2 Photodiode for Optoelectronic Application. J Inorg Organomet Polym Mater 2021. [DOI: 10.1007/s10904-021-02110-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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9
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Yoo H, Heo K, Ansari MHR, Cho S. Recent Advances in Electrical Doping of 2D Semiconductor Materials: Methods, Analyses, and Applications. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:832. [PMID: 33805062 PMCID: PMC8064109 DOI: 10.3390/nano11040832] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 03/19/2021] [Accepted: 03/22/2021] [Indexed: 12/22/2022]
Abstract
Two-dimensional materials have garnered interest from the perspectives of physics, materials, and applied electronics owing to their outstanding physical and chemical properties. Advances in exfoliation and synthesis technologies have enabled preparation and electrical characterization of various atomically thin films of semiconductor transition metal dichalcogenides (TMDs). Their two-dimensional structures and electromagnetic spectra coupled to bandgaps in the visible region indicate their suitability for digital electronics and optoelectronics. To further expand the potential applications of these two-dimensional semiconductor materials, technologies capable of precisely controlling the electrical properties of the material are essential. Doping has been traditionally used to effectively change the electrical and electronic properties of materials through relatively simple processes. To change the electrical properties, substances that can donate or remove electrons are added. Doping of atomically thin two-dimensional semiconductor materials is similar to that used for silicon but has a slightly different mechanism. Three main methods with different characteristics and slightly different principles are generally used. This review presents an overview of various advanced doping techniques based on the substitutional, chemical, and charge transfer molecular doping strategies of graphene and TMDs, which are the representative 2D semiconductor materials.
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Affiliation(s)
- Hocheon Yoo
- Department of Electronic Engineering, Gachon University, 1342 Seongnamdaero, Sujeong-gu, Seongnam-si, Gyeonggi-do 13120, Korea; (H.Y.); (M.H.R.A.)
- Graduate School of IT Convergence Engineering, Gachon University, 1342 Seongnamdaero, Sujeong-gu, Seongnam-si, Gyeonggi-do 13120, Korea
| | - Keun Heo
- Department of Semiconductor Science & Technology, Jeonbuk National University, Jeonju-si, Jeollabuk-do 54896, Korea;
| | - Md. Hasan Raza Ansari
- Department of Electronic Engineering, Gachon University, 1342 Seongnamdaero, Sujeong-gu, Seongnam-si, Gyeonggi-do 13120, Korea; (H.Y.); (M.H.R.A.)
- Graduate School of IT Convergence Engineering, Gachon University, 1342 Seongnamdaero, Sujeong-gu, Seongnam-si, Gyeonggi-do 13120, Korea
| | - Seongjae Cho
- Department of Electronic Engineering, Gachon University, 1342 Seongnamdaero, Sujeong-gu, Seongnam-si, Gyeonggi-do 13120, Korea; (H.Y.); (M.H.R.A.)
- Graduate School of IT Convergence Engineering, Gachon University, 1342 Seongnamdaero, Sujeong-gu, Seongnam-si, Gyeonggi-do 13120, Korea
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10
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Lin YC, Karthikeyan J, Chang YP, Li S, Kretschmer S, Komsa HP, Chiu PW, Krasheninnikov AV, Suenaga K. Formation of Highly Doped Nanostripes in 2D Transition Metal Dichalcogenides via a Dislocation Climb Mechanism. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2007819. [PMID: 33604926 DOI: 10.1002/adma.202007819] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 12/21/2020] [Indexed: 06/12/2023]
Abstract
Doping of materials beyond the dopant solubility limit remains a challenge, especially when spatially nonuniform doping is required. In 2D materials with a high surface-to-volume ratio, such as transition metal dichalcogenides, various post-synthesis approaches to doping have been demonstrated, but full control over spatial distribution of dopants remains a challenge. A post-growth doping of single layers of WSe2 is performed by adding transition metal (TM) atoms in a two-step process, which includes annealing followed by deposition of dopants together with Se or S. The Ti, V, Cr, and Fe impurities at W sites are identified by using transmission electron microscopy and electron energy loss spectroscopy. Remarkably, an extremely high density (6.4-15%) of various types of impurity atoms is achieved. The dopants are revealed to be largely confined within nanostripes embedded in the otherwise pristine WSe2 . Density functional theory calculations show that the dislocations assist the incorporation of the dopant during their climb and give rise to stripes of TM dopant atoms. This work demonstrates a possible spatially controllable doping strategy to achieve the desired local electronic, magnetic, and optical properties in 2D materials.
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Affiliation(s)
- Yung-Chang Lin
- Nanomaterials Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, 305-8565, Japan
| | - Jeyakumar Karthikeyan
- Department of Applied Physics, Aalto University, P. O. Box 11100, Aalto, 00076, Finland
- Department of Basic Sciences and Humanities, Rajiv Gandhi Institute of Petroleum Technology, Jais, Amethi, Uttar Pradesh, 229304, India
| | - Yao-Pang Chang
- Department of Electrical Engineering, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Shisheng Li
- International Center for Young Scientists (ICYS), National Institute for Materials Science (NIMS), Tsukuba, 305-0044, Japan
| | - Silvan Kretschmer
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328, Dresden, Germany
| | - Hannu-Pekka Komsa
- Department of Applied Physics, Aalto University, P. O. Box 11100, Aalto, 00076, Finland
- Microelectronics Research Unit, University of Oulu, P. O. Box 8000, Oulu, 90014, Finland
| | - Po-Wen Chiu
- Department of Electrical Engineering, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Arkady V Krasheninnikov
- Department of Applied Physics, Aalto University, P. O. Box 11100, Aalto, 00076, Finland
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328, Dresden, Germany
| | - Kazu Suenaga
- Nanomaterials Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, 305-8565, Japan
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11
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Chaves FA, Feijoo PC, Jiménez D. 2D pn junctions driven out-of-equilibrium. NANOSCALE ADVANCES 2020; 2:3252-3262. [PMID: 36134281 PMCID: PMC9419719 DOI: 10.1039/d0na00267d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 06/08/2020] [Indexed: 05/25/2023]
Abstract
The pn junction is a fundamental electrical component in modern electronics and optoelectronics. Currently, there is a great deal of interest in the two-dimensional (2D) pn junction. Although many experiments have demonstrated the working principle, there is a lack of fundamental understanding of its basic properties and expected performances, in particular when the device is driven out-of-equilibrium. To fill the current gap in understanding, we investigate the electrostatics and electronic transport of 2D lateral pn junctions. To do so we implement a physics-based simulator that self-consistently solves the 2D Poisson's equation coupled to the drift-diffusion and continuity equations. Notably, the simulator takes into account the strong influence of the out-of-plane electric field through the surrounding dielectric, capturing the weak screening of charge carriers. Supported by simulations, we propose a Shockley-like equation for the ideal current-voltage (J-V) characteristics, in full analogy to the bulk junction after defining an effective depletion layer (EDL). We also discuss the impact of recombination-generation processes inside the EDL, which actually produce a significant deviation with respect to the ideal behavior, consistently with experimental data. Moreover, we analyze the capacitances and conductance of the 2D lateral pn junction. Based on its equivalent circuit we investigate its cut-off frequency targeting RF applications. To gain deeper insight into the role played by material dimensionality, we benchmark the performances of single-layer MoS2 (2D) lateral pn junctions against those of the Si (3D) junction. Finally, a practical discussion on the short length 2D junction case together with the expected impact of interface states has been provided. Given the available list of 2D materials, this work opens the door to a wider exploration of material-dependent performances.
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Affiliation(s)
- Ferney A Chaves
- Departament d'Enginyeria Electrònica, Escola d'Enginyeria, Universitat Autònoma de Barcelona Campus UAB 08193 Bellaterra Spain
| | - Pedro C Feijoo
- Departament d'Enginyeria Electrònica, Escola d'Enginyeria, Universitat Autònoma de Barcelona Campus UAB 08193 Bellaterra Spain
| | - David Jiménez
- Departament d'Enginyeria Electrònica, Escola d'Enginyeria, Universitat Autònoma de Barcelona Campus UAB 08193 Bellaterra Spain
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