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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: 34] [Impact Index Per Article: 11.3] [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.
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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
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52
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Kumar S, Codony D, Arias I, Suryanarayana P. Flexoelectricity in atomic monolayers from first principles. NANOSCALE 2021; 13:1600-1607. [PMID: 33427828 DOI: 10.1039/d0nr07803d] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We study the flexoelectric effect in fifty-four select atomic monolayers using ab initio Density Functional Theory (DFT). Specifically, considering representative materials from each of the Group III monochalcogenides, transition metal dichalcogenides (TMDs), Groups IV, III-V, and V monolayers, Group IV dichalcogenides, Group IV monochalcogenides, transition metal trichalcogenides (TMTs), and Group V chalcogenides, we perform symmetry-adapted DFT simulations to calculate transversal flexoelectric coefficients along the principal directions at practically relevant bending curvatures. We find that the materials demonstrate linear behavior and have similar coefficients along both principal directions, with values for TMTs being up to a factor of five larger than those of graphene. In addition, we find electronic origins for the flexoelectric effect, which increases with monolayer thickness, elastic modulus along the bending direction, and sum of polarizability of constituent atoms.
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Affiliation(s)
- Shashikant Kumar
- College of Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.
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Zheng H, Lu Y, Ye KH, Hu J, Liu S, Yan J, Ye Y, Guo Y, Lin Z, Cheng J, Cao Y. Atomically thin photoanode of InSe/graphene heterostructure. Nat Commun 2021; 12:91. [PMID: 33398029 PMCID: PMC7782821 DOI: 10.1038/s41467-020-20341-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 11/25/2020] [Indexed: 11/09/2022] Open
Abstract
Achieving high-efficiency photoelectrochemical water splitting requires a better understanding of ion kinetics, e.g., diffusion, adsorption and reactions, near the photoelectrode's surface. However, with macroscopic three-dimensional electrodes, it is often difficult to disentangle the contributions of surface effects to the total photocurrent from that of various factors in the bulk. Here, we report a photoanode made from a InSe crystal monolayer that is encapsulated with monolayer graphene to ensure high stability. We choose InSe among other photoresponsive two-dimensional (2D) materials because of its unique properties of high mobility and strongly suppressing electron-hole pair recombination. Using the atomically thin electrodes, we obtained a photocurrent with a density >10 mA cm-2 at 1.23 V versus reversible hydrogen electrode, which is several orders of magnitude greater than other 2D photoelectrodes. In addition to the outstanding characteristics of InSe, we attribute the enhanced photocurrent to the strong coupling between the hydroxide ions and photo-generated holes near the anode surface. As a result, a persistent current even after illumination ceased was also observed due to the presence of ions trapped holes with suppressed electron-hole recombination. Our results provide atomically thin materials as a platform for investigating ion kinetics at the electrode surface and shed light on developing next-generation photoelectrodes with high efficiency.
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Affiliation(s)
- Haihong Zheng
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Yizhen Lu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Kai-Hang Ye
- Guangzhou Key Laboratory of Clean Transportation Energy Chemistry, School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou, 510006, China
| | - Jinyuan Hu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Shuai Liu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Jiawei Yan
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Yu Ye
- State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing, 100871, China
| | - Yuxi Guo
- Guangzhou Key Laboratory of Clean Transportation Energy Chemistry, School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou, 510006, China
| | - Zhan Lin
- Guangzhou Key Laboratory of Clean Transportation Energy Chemistry, School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou, 510006, China
| | - Jun Cheng
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.
| | - Yang Cao
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China. .,Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen, 361005, China.
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54
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Wang D, Ju W, Li T, Zhou Q, Zhang Y, Gao Z, Kang D, Li H, Gong S. Dipole control of Rashba spin splitting in a type-II Sb/InSe van der Waals heterostructure. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 33:045501. [PMID: 32987372 DOI: 10.1088/1361-648x/abbc35] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 09/28/2020] [Indexed: 06/11/2023]
Abstract
InSe monolayer, belonging to group III-VI chalcogenide family, has shown promising performance in the realm of spintronic. Nevertheless, the out-of-plane mirror symmetry in InSe monolayer constrains the electrons' degrees of freedom, and this will confine its spin-related applications. Herein, we construct Sb/InSe van der Waals heterostructure to extend the electronic and spintronic properties of InSe. The density functional theory is utilized to verify the tunable electronic properties and Rashba spin splitting (RSS) of Sb/InSe heterostructure. According to the obtained results, the Sb/InSe heterostructure can be considered as a direct band gap semiconductor with typical type-II band alignment, where the electrons and holes are localized in the InSe and Sb layers, respectively. The RSS is recognized at conduction band minimum around Γ point in Sb/InSe, which is induced by the spontaneous internal electric field with electric dipole moment of 0.016 e Å from Sb to InSe. The vertical strain, in-plane strain, and external electric field are employed to modulate the strength of RSS. The Rashba coefficient and dipole moment exhibit the similar variation tendency, suggesting the strength of RSS depends on the magnitude of dipole moment. The controllable RSS makes Sb/InSe heterostructure become an appropriate candidate material for spintronic devices.
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Affiliation(s)
- Donghui Wang
- College of Physics and Engineering, Henan Key Laboratory of Photoelectric Energy Storage Materials and Applications, Henan University of Science and Technology, Luoyang 471023, People's Republic of China
| | - Weiwei Ju
- College of Physics and Engineering, Henan Key Laboratory of Photoelectric Energy Storage Materials and Applications, Henan University of Science and Technology, Luoyang 471023, People's Republic of China
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, People's Republic of China
| | - Tongwei Li
- College of Physics and Engineering, Henan Key Laboratory of Photoelectric Energy Storage Materials and Applications, Henan University of Science and Technology, Luoyang 471023, People's Republic of China
| | - Qingxiao Zhou
- College of Physics and Engineering, Henan Key Laboratory of Photoelectric Energy Storage Materials and Applications, Henan University of Science and Technology, Luoyang 471023, People's Republic of China
| | - Yi Zhang
- College of Physics and Engineering, Henan Key Laboratory of Photoelectric Energy Storage Materials and Applications, Henan University of Science and Technology, Luoyang 471023, People's Republic of China
| | - Zijian Gao
- College of Physics and Engineering, Henan Key Laboratory of Photoelectric Energy Storage Materials and Applications, Henan University of Science and Technology, Luoyang 471023, People's Republic of China
| | - Dawei Kang
- College of Physics and Engineering, Henan Key Laboratory of Photoelectric Energy Storage Materials and Applications, Henan University of Science and Technology, Luoyang 471023, People's Republic of China
| | - Haisheng Li
- College of Physics and Engineering, Henan Key Laboratory of Photoelectric Energy Storage Materials and Applications, Henan University of Science and Technology, Luoyang 471023, People's Republic of China
| | - Shijing Gong
- Department of optoelectrics, East China Normal University, Shanghai 200062, People's Republic of China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, People's Republic of China
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Kumar AS, Wang M, Li Y, Fujita R, Gao XPA. Interfacial Charge Transfer and Gate-Induced Hysteresis in Monochalcogenide InSe/GaSe Heterostructures. ACS APPLIED MATERIALS & INTERFACES 2020; 12:46854-46861. [PMID: 32955239 DOI: 10.1021/acsami.0c09635] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Heterostructures of two-dimensional (2D) van der Waals semiconductor materials offer a diverse playground for exploring fundamental physics and potential device applications. In InSe/GaSe heterostructures formed by sequential mechanical exfoliation and stacking of 2D monochalcogenides InSe and GaSe, we observe charge transfer between InSe and GaSe because of the 2D van der Waals interface formation and a strong hysteresis effect in the electron transport through the InSe layer when a gate voltage is applied through the GaSe layer. A gate voltage-dependent conductance decay rate is also observed. We relate these observations to the gate voltage-dependent dynamical charge transfer between InSe and GaSe layers.
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Affiliation(s)
- Arvind Shankar Kumar
- Department of Physics, Case Western Reserve University, 2076 Adelbert Road, Cleveland, Ohio 44106, United States
| | - Mingyuan Wang
- Department of Physics, Case Western Reserve University, 2076 Adelbert Road, Cleveland, Ohio 44106, United States
| | - Yancheng Li
- Department of Physics, Case Western Reserve University, 2076 Adelbert Road, Cleveland, Ohio 44106, United States
| | - Ryuji Fujita
- Department of Physics, Oxford University, Parks Road, Oxford OX1 3PU, U.K
| | - Xuan P A Gao
- Department of Physics, Case Western Reserve University, 2076 Adelbert Road, Cleveland, Ohio 44106, United States
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56
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Hao Q, Liu J, Dong W, Yi H, Ke Y, Tang S, Qi D, Zhang W. Visible to near-infrared photodetector with novel optoelectronic performance based on graphene/S-doped InSe heterostructure on h-BN substrate. NANOSCALE 2020; 12:19259-19266. [PMID: 32930698 DOI: 10.1039/d0nr04338a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
van der Waals heterostructures of two-dimensional (2D) materials have attracted considerable attention due to their flexibility in the design of new functional devices. Despite numerous studies on graphene/2D semiconductor heterostructures, their optoelectronic applications are significantly hindered because of several disadvantages, such as large band gaps and chemical instability. In this work, we demonstrate the fabrication of graphene/S-doped InSe heterostructure photodetectors with excellent photoresponse performance, and this is attributed to the moderate band gap and band gap engineering by element doping of InSe as well as the high carrier mobility of graphene. In particular, the graphene/InSe0.9S0.1 device achieves an ultrahigh photoresponsivity of ∼4.9 × 106 A W-1 at 700 nm and an EQE of 8.7 × 108%, and it exhibits broadband photodetection (visible to near-infrared). More importantly, by virtue of the interaction between n-type graphene arising from the influence of h-BN as a dielectric layer and S-doped InSe with a high work-function, our devices always exhibited positive photocurrent when the polarity of the gate voltage is adjusted, and is different from that the previously reported graphene/2D semiconductor photodetectors. This work not only provides a promising platform for highly efficient broadband photodetectors but also sheds light on tuning the optoelectronic performance through band gap engineering and designing novel heterostructures-based various 2D materials.
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Affiliation(s)
- Qiaoyan Hao
- International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, Shenzhen University, Shenzhen 518060, China.
| | - Jidong Liu
- International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, Shenzhen University, Shenzhen 518060, China.
| | - Weilong Dong
- International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, Shenzhen University, Shenzhen 518060, China.
| | - Huan Yi
- International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, Shenzhen University, Shenzhen 518060, China.
| | - Yuxuan Ke
- International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, Shenzhen University, Shenzhen 518060, China.
| | - Sisi Tang
- International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, Shenzhen University, Shenzhen 518060, China.
| | - Dianyu Qi
- International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, Shenzhen University, Shenzhen 518060, China.
| | - Wenjing Zhang
- International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, Shenzhen University, Shenzhen 518060, China.
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57
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Sheng W, Xu Y, Liu M, Nie G, Wang J, Gong S. The InSe/SiH type-II van der Waals heterostructure as a promising water splitting photocatalyst: a first-principles study. Phys Chem Chem Phys 2020; 22:21436-21444. [PMID: 32945319 DOI: 10.1039/d0cp03831h] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Photocatalytic water splitting for hydrogen production has attracted increasing research attention in recent years, and great efforts have been made in order to find the ideal photocatalyst. In this work, we proposed a two-dimensional material-based van der Waals (vdW) heterostructure constructed by vertically stacked indium selenide (InSe) and silicane (SiH) and studied the feasibility of using it as a possible photocatalyst for water splitting by using first-principles methods. The results show that the InSe/SiH is a direct band gap semiconductor with appropriate gap value and band edge position for photocatalysts in water splitting. Importantly, this heterostructure presents type-II band alignment at the equilibrium configuration, which supports the effective separation of photoexcited electrons and holes. A built-in electric field set up within the interface of the heterostructure will further hinder the electron-hole recombination and thus improve the photocatalytic efficiency. In addition, compared with separated InSe and SiH monolayers, the heterostructure exhibits enhanced light absorption capabilities in ultraviolet and visible light regions. These findings indicate that the InSe/SiH vdW heterostructure is a promising candidate for photocatalysts for solar water splitting.
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Affiliation(s)
- Wei Sheng
- School of Physics and Electronic Science, Hunan University of Science and Technology, Xiangtan 411201, China.
| | - Ying Xu
- School of Physics and Electronic Science, Hunan University of Science and Technology, Xiangtan 411201, China.
| | - Mingwei Liu
- School of Physics and Electronic Science, Hunan University of Science and Technology, Xiangtan 411201, China.
| | - Guozheng Nie
- School of Physics and Electronic Science, Hunan University of Science and Technology, Xiangtan 411201, China.
| | - Junnian Wang
- School of Physics and Electronic Science, Hunan University of Science and Technology, Xiangtan 411201, China.
| | - Shijing Gong
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China and Department of Electronic Engineering, Key Laboratory of Polar Materials and Devices (MOE), School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China
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58
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Hao Q, Liu J, Wang G, Chen J, Gan H, Zhu J, Ke Y, Chai Y, Lin J, Zhang W. Surface-Modified Ultrathin InSe Nanosheets with Enhanced Stability and Photoluminescence for High-Performance Optoelectronics. ACS NANO 2020; 14:11373-11382. [PMID: 32809802 DOI: 10.1021/acsnano.0c03556] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Indium selenide (InSe) has become a research hotspot because of its favorable carrier mobility and thickness-tunable band gap, showing great application potential in high-performance optoelectronic devices. The trend of miniaturization in optoelectronics has forced the feature sizes of the electronic components to shrink accordingly. Therefore, atomically thin InSe crystals may play an important role in future optoelectronics. Given the instability and ultralow photoluminescent (PL) emission of mechanically exfoliated ultrathin InSe, synthesis of highly stable mono- and few-layer InSe nanosheets with high PL efficiency has become crucial. Herein, ultrathin InSe nanosheets were prepared via thermal annealing of electrochemically intercalated products from bulk InSe. The size and yield of the as-prepared nanosheets were up to ∼160 μm and ∼70%, respectively, and ∼80% of the nanosheets were less than five layer. Impressively, the as-prepared nanosheets showed greatly enhanced stability and PL emission because of surface modification by carbon species. Efficient photoresponsivity of 2 A/W was achieved in the as-prepared nanosheet-based devices. These nanosheets were further assembled into large-area thin films with photoresponsivity of 16 A/W and an average Hall mobility of about 5 cm2 V-1 s-1. Finally, one-dimensional (1D) InSe nanoscrolls with a length up to 90 μm were constructed by solvent-assisted self-assembly of the exfoliated nanosheets.
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Affiliation(s)
- Qiaoyan Hao
- International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, Shenzhen University, Shenzhen 518060, China
| | - Jidong Liu
- International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, Shenzhen University, Shenzhen 518060, China
| | - Gang Wang
- Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
| | - Jiewei Chen
- Department of Applied Physics, Hong Kong Polytechnic University, Hong Kong 999077, China
| | - Haibo Gan
- International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, Shenzhen University, Shenzhen 518060, China
| | - Jiaqi Zhu
- International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, Shenzhen University, Shenzhen 518060, China
| | - Yuxuan Ke
- International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, Shenzhen University, Shenzhen 518060, China
| | - Yang Chai
- Department of Applied Physics, Hong Kong Polytechnic University, Hong Kong 999077, China
| | - Junhao Lin
- Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
| | - Wenjing Zhang
- International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, Shenzhen University, Shenzhen 518060, China
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Wang Y, Gao J, Wei B, Han Y, Wang C, Gao Y, Liu H, Han L, Zhang Y. Reduction of the ambient effect in multilayer InSe transistors and a strategy toward stable 2D-based optoelectronic applications. NANOSCALE 2020; 12:18356-18362. [PMID: 32870216 DOI: 10.1039/d0nr04120c] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Indium selenide (InSe) photodetection devices attract significant research interest. However, InSe is unstable and degrades rapidly in ambient conditions, thus it is still a challenge to fabricate stable optoelectronic devices. In this work, multilayer InSe FETs are fabricated, and their photoresponse properties are investigated. Both positive and negative photoconductivities are observed for the first time in the same InSe FET in a wide spectral range from 450 nm to 660 nm, which can be tuned through changing either the gate bias or the source-drain bias. A physical mechanism is proposed to explain the dual-photoresponse phenomenon in our devices. Based on the proposed physical mechanism, as a proof of concept, a facile and simple approach is used to eliminate the negative photoconductivity of the InSe FET. Our results will offer valuable strategies for stable multilayer InSe optoelectronic device design, and a practical scheme for improving the performance of other transition metal dichalcogenide devices as well.
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Affiliation(s)
- Yanhao Wang
- Institute of Marine Science and Technology, Shandong University, Qingdao 266237, China.
| | - Jianwei Gao
- Institute of Marine Science and Technology, Shandong University, Qingdao 266237, China.
| | - Bin Wei
- School of Microelectronics, Shandong University, Jinan 250010, China
| | - Yingkuan Han
- School of Microelectronics, Shandong University, Jinan 250010, China
| | - Chao Wang
- Institute of Marine Science and Technology, Shandong University, Qingdao 266237, China.
| | - Yakun Gao
- Institute of Marine Science and Technology, Shandong University, Qingdao 266237, China.
| | - Hong Liu
- State Key Laboratory of Crystal Materials, Shandong University, Jinan 250010, China. and Collaborative Innovation Center of Technology and Equipment for Biological Diagnosis and Therapy in Universities of Shandong, Institute for Advanced Interdisciplinary Research (iAIR), University of Jinan, Jinan 250010, China
| | - Lin Han
- Institute of Marine Science and Technology, Shandong University, Qingdao 266237, China.
| | - Yu Zhang
- Institute of Marine Science and Technology, Shandong University, Qingdao 266237, China.
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60
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Pham VT, Fang TH. Effects of temperature and intrinsic structural defects on mechanical properties and thermal conductivities of InSe monolayers. Sci Rep 2020; 10:15082. [PMID: 32934331 PMCID: PMC7492280 DOI: 10.1038/s41598-020-72162-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 08/26/2020] [Indexed: 11/08/2022] Open
Abstract
We conduct molecular dynamics simulations to study the mechanical and thermal properties of monolayer indium selenide (InSe) sheets. The influences of temperature, intrinsic structural defect on the tensile properties were assessed by tensile strength, fracture strain, and Young's modulus. We found that the tensile strength, fracture strain, and Young's modulus reduce as increasing temperature. The results also indicate that with the existence of defects, the stress is concentrated at the region around the vacancy leading to the easier destruction. Therefore, the mechanical properties were considerably decreased with intrinsic structural defects. Moreover, Young's modulus is isotropy in both zigzag and armchair directions. The point defect almost has no influence on Young's modulus but it strongly influences the ultimate strength and fracture strain. Besides, the effects of temperature, length size, vacancy defect on thermal conductivity (κ) of monolayer InSe sheets were also studied by using none-equilibrium molecular dynamics simulations. The κ significantly arises as increasing the length of InSe sheets. The κ of monolayer InSe with infinite length at 300 K in armchair direction is 46.18 W/m K, while in zigzag direction is 45.87 W/m K. The difference of κ values in both directions is very small, indicating the isotropic properties in thermal conduction of this material. The κ decrease as increasing the temperature. The κ goes down with the number of atoms vacancy defect increases.
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Affiliation(s)
- Van-Trung Pham
- Department of Mechanical Engineering, National Kaohsiung University of Science and Technology, Kaohsiung, 807, Taiwan
- Institute of Research and Development, Duy Tan University, Danang, 550000, Vietnam
| | - Te-Hua Fang
- Department of Mechanical Engineering, National Kaohsiung University of Science and Technology, Kaohsiung, 807, Taiwan.
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Zhang W, Shi C, He C, Bai M. External-strain induced transition from Schottky to ohmic contact in Graphene/InS and Graphene/Janus In2SSe heterostructures. J SOLID STATE CHEM 2020. [DOI: 10.1016/j.jssc.2020.121511] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Chen F, Cui A, Wang X, Gao C, Xu L, Jiang K, Zhang J, Hu Z, Chu J. Lattice vibration characteristics in layered InSe films and the electronic behavior of field-effect transistors. NANOTECHNOLOGY 2020; 31:335702. [PMID: 32344392 DOI: 10.1088/1361-6528/ab8df1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Understanding how temperature affects the structural and electronic properties for two-dimensional (2D) semiconductors could promote the application and development of nanoelectronic devices. Here, the temperature dependence of lattice structure for indium selenide (InSe) nanosheets and the corresponding electronic properties of 3 nm indium-deposited InSe field-effect transistors (FETs) are systematically demonstrated. Analyses of Raman spectra suggest that the difference of phonon frequency (Δω) for the A[Formula: see text] mode is found to be 3.14 cm-1, which is larger than that of the E[Formula: see text] mode due to the stronger electron-phonon coupling for the A[Formula: see text] mode. The device performance based on indium-deposited InSe is systematically explained using Kelvin probe force microscopy (KPFM) and the predicted energy band structure. Furthermore, FETs based on temperature and variable thickness InSe flakes are designed as applicable devices. Our findings are of fundamental importance to explain the underlying physics in intrinsic InSe transistors and improve further applications.
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Affiliation(s)
- Fangfang Chen
- Technical Center for Multifunctional Magneto-Optical Spectroscopy (Shanghai), Engineering Research Center of Nanophotonics Advanced Instrument (Ministry of Education), Department of Materials, School of Physics and Electronic Science, East China Normal University, Shanghai 200241, People's Republic of China
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63
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Sun Y, Li Y, Li T, Biswas K, Patanè A, Zhang L. New Polymorphs of 2D Indium Selenide with Enhanced Electronic Properties. ADVANCED FUNCTIONAL MATERIALS 2020; 30:2001920. [PMID: 32774197 PMCID: PMC7405953 DOI: 10.1002/adfm.202001920] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 04/22/2020] [Accepted: 04/23/2020] [Indexed: 05/05/2023]
Abstract
The 2D semiconductor indium selenide (InSe) has attracted significant interest due its unique electronic band structure, high electron mobility, and wide tunability of its band gap energy achieved by varying the layer thickness. All these features make 2D InSe a potential candidate for advanced electronic and optoelectronic applications. Here, the discovery of new polymorphs of InSe with enhanced electronic properties is reported. Using a global structure search that combines artificial swarm intelligence with first-principles energetic calculations, polymorphs that consist of a centrosymmetric monolayer belonging to the point group D 3d are identified, distinct from well-known polymorphs based on the D 3h monolayers that lack inversion symmetry. The new polymorphs are thermodynamically and kinetically stable, and exhibit a wider optical spectral response and larger electron mobilities compared to the known polymorphs. Opportunities to synthesize these newly discovered polymorphs and viable routes to identify them by X-ray diffraction, Raman spectroscopy, and second harmonic generation experiments are discussed.
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Affiliation(s)
- Yuanhui Sun
- State Key Laboratory of Integrated OptoelectronicsKey Laboratory of Automobile Materials of MOE and College of Materials Science and EngineeringJilin UniversityChangchun130012China
| | - Yawen Li
- State Key Laboratory of Integrated OptoelectronicsKey Laboratory of Automobile Materials of MOE and College of Materials Science and EngineeringJilin UniversityChangchun130012China
| | - Tianshu Li
- State Key Laboratory of Integrated OptoelectronicsKey Laboratory of Automobile Materials of MOE and College of Materials Science and EngineeringJilin UniversityChangchun130012China
| | - Koushik Biswas
- Department of Chemistry and PhysicsArkansas State UniversityJonesboroAR72467USA
| | - Amalia Patanè
- School of Physics and AstronomyThe University of NottinghamNottinghamNG7 2RDUK
| | - Lijun Zhang
- State Key Laboratory of Integrated OptoelectronicsKey Laboratory of Automobile Materials of MOE and College of Materials Science and EngineeringJilin UniversityChangchun130012China
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64
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Lyu F, Sun Y, Yang Q, Tang B, Li M, Li Z, Sun M, Gao P, Ye LH, Chen Q. Thickness-dependent band gap of α-In 2Se 3: from electron energy loss spectroscopy to density functional theory calculations. NANOTECHNOLOGY 2020; 31:315711. [PMID: 32294630 DOI: 10.1088/1361-6528/ab8998] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
α-In2Se3 has attracted increasing attention in recent years due to its excellent electrical and optical properties. Especially, attention has been paid to its peculiar ferroelectric and piezoelectric properties which most other two-dimensional (2D) materials do not possess. This paper presents the first measurement of the thickness-dependent band gaps of few-layer α-In2Se3 by electron energy loss spectroscopy (EELS). The band gap increases with decreasing film thickness which varies from 1.44 eV in a 48 nm thick area to 1.64 eV in an 8 nm thick area of the samples. Further, by combining the improved exchange-correlation potential and proper screening of the internal electric field in an advanced 2D electronic structure technique, we have been able to obtain the structural dependence of the band gap within density functional theory up to hundreds of atoms. This is also the first calculation of a similar type for 2D ferroelectric materials. Both experiment and theory suggest that the variation of the band gap of α-In2Se3 fits well with the quantum confinement model for 2D materials.
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Affiliation(s)
- Fengjiao Lyu
- Key Laboratory for the Physics and Chemistry of Nanodevices, Department of Electronics, Peking University, Beijing 100871, People's Republic of China
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Wei TR, Jin M, Wang Y, Chen H, Gao Z, Zhao K, Qiu P, Shan Z, Jiang J, Li R, Chen L, He J, Shi X. Exceptional plasticity in the bulk single-crystalline van der Waals semiconductor InSe. Science 2020; 369:542-545. [DOI: 10.1126/science.aba9778] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 06/08/2020] [Indexed: 11/02/2022]
Abstract
Inorganic semiconductors are vital for a number of critical applications but are almost universally brittle. Here, we report the superplastic deformability of indium selenide (InSe). Bulk single-crystalline InSe can be compressed by orders of magnitude and morphed into a Möbius strip or a simple origami at room temperature. The exceptional plasticity of this two-dimensional van der Waals inorganic semiconductor is attributed to the interlayer gliding and cross-layer dislocation slip that are mediated by the long-range In-Se Coulomb interaction across the van der Waals gap and soft intralayer In-Se bonding. We propose a combinatory deformability indicator (Ξ) to prescreen candidate bulk semiconductors for use in next-generation deformable or flexible electronics.
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Affiliation(s)
- Tian-Ran Wei
- State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
| | - Min Jin
- College of Materials, Shanghai Dianji University, Shanghai 201306, China
| | - Yuecun Wang
- Center for Advancing Materials Performance from the Nanoscale (CAMP-Nano) and Hysitron Applied Research Center in China (HARCC), State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049, China
| | - Hongyi Chen
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
| | - Zhiqiang Gao
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
| | - Kunpeng Zhao
- State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
| | - Pengfei Qiu
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
| | - Zhiwei Shan
- Center for Advancing Materials Performance from the Nanoscale (CAMP-Nano) and Hysitron Applied Research Center in China (HARCC), State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049, China
| | - Jun Jiang
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
| | - Rongbin Li
- College of Materials, Shanghai Dianji University, Shanghai 201306, China
| | - Lidong Chen
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
| | - Jian He
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634-0978, USA
| | - Xun Shi
- State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
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Ho CH. Ga 2Se 3 Defect Semiconductors: The Study of Direct Band Edge and Optical Properties. ACS OMEGA 2020; 5:18527-18534. [PMID: 32743231 PMCID: PMC7392520 DOI: 10.1021/acsomega.0c02623] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 07/06/2020] [Indexed: 06/11/2023]
Abstract
Direct band edge is a crucial factor for a functional chalcogenide to be applied in luminescence devices, photodetectors, and solar-energy devices. In this work, the room-temperature band-edge emission of III-VI Ga2Se3 has been first observed by micro-photoluminescence (μPL) measurement. The emission peak is at 1.85 eV, which matches well with the band-edge transition that is measured by micro-thermoreflectance (μTR) and micro-transmittance (μTransmittance) for verification of the direct band edge of Ga2Se3. The temperature-dependent μTR spectra of Ga2Se3 show a general semiconductor behavior with its temperature-energy shift following Varshni-type variation. With the well-evident direct band edge, the peak responsivities of photovoltaic response (∼6.2 mV/μW) and photocurrent (∼2.25 μA/μW at f = 30 Hz) of defect zincblende Ga2Se3 can be, respectively, detected at ∼2.22 and ∼1.92 eV from a Cu/Ga2Se3 Schottky solar cell and a Ga2Se3 photoconductor. On the basis of experimental analysis, the optical band edge and photoresponsivity properties of a III-VI Ga2Se3 defect semiconductor are thus realized.
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Affiliation(s)
- Ching-Hwa Ho
- Graduate Institute of Applied
Science and Technology, National Taiwan
University of Science and Technology, Taipei 106, Taiwan
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Andres-Penares D, Canet-Albiach R, Noguera-Gomez J, Martínez-Pastor JP, Abargues R, Sánchez-Royo JF. Two-Dimensional Indium Selenide for Sulphur Vapour Sensing Applications. NANOMATERIALS 2020; 10:nano10071396. [PMID: 32708372 PMCID: PMC7408355 DOI: 10.3390/nano10071396] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 07/10/2020] [Accepted: 07/14/2020] [Indexed: 01/25/2023]
Abstract
Surface-to-volume ratio in two-dimensional (2D) materials highlights among their characteristics as an inherent and intrinsic advantage taking into account their strong sensitivity to surface effects. For this reason, we have proposed in this work micromechanically exfoliated 2D nanosheets of InSe as an optical vapour sensor. As a proof of concept, we used 2-mercaptoethanol as the chemical analyte in vapour phase to monitor the change of the InSe photoluminescence (PL) before and after exposure to the analyte. For short vapour exposure times (at low analyte concentration), we found a PL enhancement of InSe nanosheets attributed to the surface localization of Se defects. For long vapour exposure times (or higher concentrations) a PL reduction is observed, probably due to the diffusion of molecules within the nanosheet. These results confirm the capability of 2D InSe as a photoluminescent sensor of vapours, because of its sensitivity to surface passivation or volume diffusion of molecules.
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Affiliation(s)
- Daniel Andres-Penares
- ICMUV, Instituto de Ciencia de Materiales, Universidad de Valencia, P.O. Box 22085, 46071 Valencia, Spain; (D.A.-P.); (R.C.-A.); (J.N.-G.); (J.P.M.-P.); (R.A.)
| | - Rodolfo Canet-Albiach
- ICMUV, Instituto de Ciencia de Materiales, Universidad de Valencia, P.O. Box 22085, 46071 Valencia, Spain; (D.A.-P.); (R.C.-A.); (J.N.-G.); (J.P.M.-P.); (R.A.)
| | - Jaume Noguera-Gomez
- ICMUV, Instituto de Ciencia de Materiales, Universidad de Valencia, P.O. Box 22085, 46071 Valencia, Spain; (D.A.-P.); (R.C.-A.); (J.N.-G.); (J.P.M.-P.); (R.A.)
| | - Juan P. Martínez-Pastor
- ICMUV, Instituto de Ciencia de Materiales, Universidad de Valencia, P.O. Box 22085, 46071 Valencia, Spain; (D.A.-P.); (R.C.-A.); (J.N.-G.); (J.P.M.-P.); (R.A.)
- MATINÉE: CSIC Associated Unit-(ICMM-ICMUV of the University of Valencia), Universidad de Valencia, P.O. Box 22085, 46071 Valencia, Spain
| | - Rafael Abargues
- ICMUV, Instituto de Ciencia de Materiales, Universidad de Valencia, P.O. Box 22085, 46071 Valencia, Spain; (D.A.-P.); (R.C.-A.); (J.N.-G.); (J.P.M.-P.); (R.A.)
| | - Juan F. Sánchez-Royo
- ICMUV, Instituto de Ciencia de Materiales, Universidad de Valencia, P.O. Box 22085, 46071 Valencia, Spain; (D.A.-P.); (R.C.-A.); (J.N.-G.); (J.P.M.-P.); (R.A.)
- MATINÉE: CSIC Associated Unit-(ICMM-ICMUV of the University of Valencia), Universidad de Valencia, P.O. Box 22085, 46071 Valencia, Spain
- Correspondence:
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68
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Paul Inbaraj CR, Mathew RJ, Ulaganathan RK, Sankar R, Kataria M, Lin HY, Cheng HY, Lin KH, Lin HI, Liao YM, Chou FC, Chen YT, Lee CH, Chen YF. Modulating Charge Separation with Hexagonal Boron Nitride Mediation in Vertical Van der Waals Heterostructures. ACS APPLIED MATERIALS & INTERFACES 2020; 12:26213-26221. [PMID: 32400164 DOI: 10.1021/acsami.0c06077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Tuning the optical and electrical properties by stacking different layers of two-dimensional (2D) materials enables us to create unusual physical phenomena. Here, we demonstrate an alternative approach to enhance charge separation and alter physical properties in van der Waals heterojunctions with type-II band alignment by using thin dielectric spacers. To illustrate our working principle, we implement a hexagonal boron nitride (h-BN) sieve layer in between an InSe/GeS heterojunction. The optical transitions at the junctions studied by photoluminescence and the ultrafast pump-probe technique show quenching of emission without h-BN layers exhibiting an indirect recombination process. This quenching effect due to strong interlayer coupling was confirmed with Raman spectroscopic studies. In contrast, h-BN layers in between InSe and GeS show strong enhancement in emission, giving another degree of freedom to tune the heterojunction property. The two-terminal photoresponse study supports the argument by showing a large photocurrent density for an InSe/h-BN/GeS device by avoiding interlayer charge recombination. The enhanced charge separation with h-BN mediation manifests a photoresponsivity and detectivity of 9 × 102 A W-1 and 3.4 × 1014 Jones, respectively. Moreover, a photogain of 1.7 × 103 shows a high detection of electrons for the incident photons. Interestingly, the photovoltaic short-circuit current is switched from positive to negative, whereas the open-circuit voltage changes from negative to positive. Our proposed enhancement of charge separation with 2D-insulator mediation, therefore, provides a useful route to manipulate the physical properties of heterostructures and for the future development of high-performance optoelectronic devices.
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Affiliation(s)
- Christy Roshini Paul Inbaraj
- Department of Engineering and System Science, National Tsing Hua University, Hsinchu 30013, Taiwan
- Nano-Science and Technology Program, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
| | - Roshan Jesus Mathew
- Department of Engineering and System Science, National Tsing Hua University, Hsinchu 30013, Taiwan
- Nano-Science and Technology Program, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | | | - Raman Sankar
- Center for Condensed Matter Sciences, National Taiwan University, Taipei 10617, Taiwan
- Institute of Physics, Academia Sinica, Taipei 11529, Taiwan
| | - Monika Kataria
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
- Department of Physics, National Central University, Chung-Li 320, Taiwan
- Molecular Science and Technology Program, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan
- Advanced Research Centre for Green Materials Science and Technology, National Taiwan University, Taipei 10617, Taiwan
| | - Hsia Yu Lin
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
| | - Hao-Yu Cheng
- Institute of Physics, Academia Sinica, Taipei 11529, Taiwan
| | - Kung-Hsuan Lin
- Institute of Physics, Academia Sinica, Taipei 11529, Taiwan
| | - Hung-I Lin
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
| | - Yu-Ming Liao
- Nano-Science and Technology Program, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
| | - Fang Cheng Chou
- Center for Condensed Matter Sciences, National Taiwan University, Taipei 10617, Taiwan
| | - Yit-Tsong Chen
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Chih-Hao Lee
- Department of Engineering and System Science, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Yang-Fang Chen
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
- Advanced Research Centre for Green Materials Science and Technology, National Taiwan University, Taipei 10617, Taiwan
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69
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Li S, Zhong C, Henning A, Sangwan VK, Zhou Q, Liu X, Rahn MS, Wells SA, Park HY, Luxa J, Sofer Z, Facchetti A, Darancet P, Marks TJ, Lauhon LJ, Weiss EA, Hersam MC. Molecular-Scale Characterization of Photoinduced Charge Separation in Mixed-Dimensional InSe-Organic van der Waals Heterostructures. ACS NANO 2020; 14:3509-3518. [PMID: 32078300 DOI: 10.1021/acsnano.9b09661] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Layered indium selenide (InSe) is an emerging two-dimensional semiconductor that has shown significant promise for high-performance transistors and photodetectors. The range of optoelectronic applications for InSe can potentially be broadened by forming mixed-dimensional van der Waals heterostructures with zero-dimensional molecular systems that are widely employed in organic electronics and photovoltaics. Here, we report the spatially resolved investigation of photoinduced charge separation between InSe and two molecules (C70 and C8-BTBT) using scanning tunneling microscopy combined with laser illumination. We experimentally and computationally show that InSe forms type-II and type-I heterojunctions with C70 and C8-BTBT, respectively, due to an interplay of charge transfer and dielectric screening at the interface. Laser-excited scanning tunneling spectroscopy reveals a ∼0.25 eV decrease in the energy of the lowest unoccupied molecular orbital of C70 with optical illumination. Furthermore, photoluminescence spectroscopy and Kelvin probe force microscopy indicate that electron transfer from InSe to C70 in the type-II heterojunction induces a photovoltage that quantitatively matches the observed downshift in the tunneling spectra. In contrast, no significant changes are observed upon optical illumination in the type-I heterojunction formed between InSe and C8-BTBT. Density functional theory calculations further show that, despite the weak coupling between the molecular species and InSe, the band alignment of these mixed-dimensional heterostructures strongly differs from the one suggested by the ionization potential and electronic affinities of the isolated components. Self-energy-corrected density functional theory indicates that these effects are the result of the combination of charge redistribution at the interface and heterogeneous dielectric screening of the electron-electron interactions in the heterostructure. In addition to providing specific insight for mixed-dimensional InSe-organic van der Waals heterostructures, this work establishes a general experimental methodology for studying localized charge transfer at the molecular scale that is applicable to other photoactive nanoscale systems.
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Affiliation(s)
- Shaowei Li
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208-3108, United States
| | - Chengmei Zhong
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208-3108, United States
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Alex Henning
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208-3108, United States
| | - Vinod K Sangwan
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208-3108, United States
| | - Qunfei Zhou
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, Illinois 60439, United States
- Northwestern Argonne Institute for Science and Engineering, Evanston, Illinois 60208, United States
| | - Xiaolong Liu
- Applied Physics Graduate Program, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Matthew S Rahn
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208-3108, United States
| | - Spencer A Wells
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208-3108, United States
| | - Hong Youl Park
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208-3108, United States
| | - Jan Luxa
- Department of Inorganic Chemistry, University of Chemistry and Technology Prague, Technicka 5, 166 28 Prague 6, Czech Republic
| | - Zdeněk Sofer
- Department of Inorganic Chemistry, University of Chemistry and Technology Prague, Technicka 5, 166 28 Prague 6, Czech Republic
| | - Antonio Facchetti
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Pierre Darancet
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, Illinois 60439, United States
- Northwestern Argonne Institute for Science and Engineering, Evanston, Illinois 60208, United States
| | - Tobin J Marks
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Lincoln J Lauhon
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208-3108, United States
| | - Emily A Weiss
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Mark C Hersam
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208-3108, United States
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113, United States
- Applied Physics Graduate Program, Northwestern University, Evanston, Illinois 60208-3113, United States
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70
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Qin F, Hu Y, Hu P, Feng W. Contact engineering high-performance ambipolar multilayer tellurium transistors. NANOTECHNOLOGY 2020; 31:115204. [PMID: 31770747 DOI: 10.1088/1361-6528/ab5bec] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Multilayer Te nanosheets have attracted increasing attention due to their high-performance electronic transport properties and good air-stability. Theoretical simulation suggests that the electronic properties of multilayer Te nanosheets could be effectively modulated by contact engineering, but most studies have reported p-type multilayer Te devices. Here, for the first time, we report on high performance ambipolar multilayer Te filed-effect-transistors (FETs) with low work function scandium (Sc, 3.58 eV), demonstrating high mobilities of 489 and 648 cm2V-1s-1 for electron and hole transport, respectively. Multilayer Te FETs with large work function metals, such as chromium (Cr, 4.5 eV), show a typical p-type transport behavior. The band structure of multilayer Te with a small bandgap and low work function Sc result in a small contact resistance (R c) for both of electron and hole transport, which leads to the ambipolar behavior of multilayer Te nanosheets. The ambipolar behavior of multilayer Te FETs indicates that contact engineering is a valid tool to tune the electrical properties of multilayer Te and raises the possibility of designing digital circuits based on multilayer Te.
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Affiliation(s)
- Fanglu Qin
- College of Chemistry, Chemical Engineering and Resource Utilization, Northeast Forestry University, Harbin, 150040, People's Republic of China
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71
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Ubrig N, Ponomarev E, Zultak J, Domaretskiy D, Zólyomi V, Terry D, Howarth J, Gutiérrez-Lezama I, Zhukov A, Kudrynskyi ZR, Kovalyuk ZD, Patané A, Taniguchi T, Watanabe K, Gorbachev RV, Fal'ko VI, Morpurgo AF. Design of van der Waals interfaces for broad-spectrum optoelectronics. NATURE MATERIALS 2020; 19:299-304. [PMID: 32015532 DOI: 10.1038/s41563-019-0601-3] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Accepted: 12/20/2019] [Indexed: 05/12/2023]
Abstract
Van der Waals (vdW) interfaces based on 2D materials are promising for optoelectronics, as interlayer transitions between different compounds allow tailoring of the spectral response over a broad range. However, issues such as lattice mismatch or a small misalignment of the constituent layers can drastically suppress electron-photon coupling for these interlayer transitions. Here, we engineered type-II interfaces by assembling atomically thin crystals that have the bottom of the conduction band and the top of the valence band at the Γ point, and thus avoid any momentum mismatch. We found that these van der Waals interfaces exhibit radiative optical transitions irrespective of the lattice constant, the rotational and/or translational alignment of the two layers or whether the constituent materials are direct or indirect gap semiconductors. Being robust and of general validity, our results broaden the scope of future optoelectronics device applications based on two-dimensional materials.
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Affiliation(s)
- Nicolas Ubrig
- Department of Quantum Matter Physics, University of Geneva, Geneva, Switzerland.
- Group of Applied Physics, University of Geneva, Geneva, Switzerland.
| | - Evgeniy Ponomarev
- Department of Quantum Matter Physics, University of Geneva, Geneva, Switzerland
- Group of Applied Physics, University of Geneva, Geneva, Switzerland
| | - Johanna Zultak
- National Graphene Institute, University of Manchester, Manchester, UK
- School of Physics & Astronomy, University of Manchester, Manchester, UK
- Henry Royce Institute for Advanced Materials, Manchester, UK
| | - Daniil Domaretskiy
- Department of Quantum Matter Physics, University of Geneva, Geneva, Switzerland
- Group of Applied Physics, University of Geneva, Geneva, Switzerland
| | - Viktor Zólyomi
- National Graphene Institute, University of Manchester, Manchester, UK
| | - Daniel Terry
- National Graphene Institute, University of Manchester, Manchester, UK
- School of Physics & Astronomy, University of Manchester, Manchester, UK
- Henry Royce Institute for Advanced Materials, Manchester, UK
| | - James Howarth
- National Graphene Institute, University of Manchester, Manchester, UK
- School of Physics & Astronomy, University of Manchester, Manchester, UK
- Henry Royce Institute for Advanced Materials, Manchester, UK
| | - Ignacio Gutiérrez-Lezama
- Department of Quantum Matter Physics, University of Geneva, Geneva, Switzerland
- Group of Applied Physics, University of Geneva, Geneva, Switzerland
| | - Alexander Zhukov
- National Graphene Institute, University of Manchester, Manchester, UK
- School of Physics & Astronomy, University of Manchester, Manchester, UK
- Henry Royce Institute for Advanced Materials, Manchester, UK
| | | | - Zakhar D Kovalyuk
- Institute for Problems of Materials Science, NAS of Ukraine, Chernivtsi Branch, Chernivtsi, Ukraine
| | - Amalia Patané
- School of Physics & Astronomy, The University of Nottingham, Nottingham, UK
| | | | - Kenji Watanabe
- National Institute for Materials Science, Tsukuba, Japan
| | - Roman V Gorbachev
- National Graphene Institute, University of Manchester, Manchester, UK
- School of Physics & Astronomy, University of Manchester, Manchester, UK
- Henry Royce Institute for Advanced Materials, Manchester, UK
| | - Vladimir I Fal'ko
- National Graphene Institute, University of Manchester, Manchester, UK.
- School of Physics & Astronomy, University of Manchester, Manchester, UK.
- Henry Royce Institute for Advanced Materials, Manchester, UK.
| | - Alberto F Morpurgo
- Department of Quantum Matter Physics, University of Geneva, Geneva, Switzerland.
- Group of Applied Physics, University of Geneva, Geneva, Switzerland.
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72
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Li Y, Ye J, Yuan K, Zhai G, Li T, Ye Y, Wu X, Zhang X. Photo-excited carrier relaxation dynamics in two-dimensional InSe flakes. NANOTECHNOLOGY 2020; 31:095713. [PMID: 31731280 DOI: 10.1088/1361-6528/ab5835] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Carrier relaxation dynamics of InSe flakes is investigated by using time-resolved pump-probe reflectivity measurement. The photocarriers associated with the P xy orbital band-edge transition at 2.40 eV, which is coupled to the in-plane polarized light, is observed to possess a lifetime of ∼19 ps at room temperature and ∼99 ps at 10 K. The temperature and power dependent carrier lifetime suggests that Shockley-Read-Hall process is the dominant nonradiative recombination mechanism responsible for the carrier relaxation. In addition, the electron scattering with a 14.5 meV optical phonon plays an active role in the carrier relaxation with increasing temperatures. A broad absorption around 1.65-1.90 eV is observed. The photocarriers associated with this broad transition show a long lifetime of ∼200 ps that is nearly independent of temperature and photon energy. This is indicative of bound carriers by defects. Our experimental results provide essential information for the characteristics of carrier dynamics and defects in InSe flakes. The experimental findings are fundamentally important for further development of microelectronics and optoelectronics based on InSe.
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Affiliation(s)
- Ying Li
- State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, People's Republic of China. Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
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73
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Shi LB, Cao S, Yang M, You Q, Zhang KC, Bao Y, Zhang YJ, Niu YY, Qian P. Theoretical prediction of intrinsic electron mobility of monolayer InSe: first-principles calculation. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:065306. [PMID: 31671411 DOI: 10.1088/1361-648x/ab534f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Recently, a novel two-dimensional (2D) semiconductor, InSe, has attracted great attention due to its potential applications in optoelectronic devices and field effect transistors. In this study, phonon-limited mobility is investigated by the first-principles calculation. At 300 K, the intrinsic electron mobilities calculated from the electron-phonon coupling (EPC) matrix element are as high as [Formula: see text] (zigzag direction) and [Formula: see text] [Formula: see text] (Armchair direction), respectively. The deformation potential theory (DPT) based on longitudinal acoustic and optical phonon scattering is also employed to investigate electron mobility. The mobility from optical phonon scattering is much higher than that from longitudinal acoustic phonon scattering. If the polarization characteristics of InSe are not considered, the electron mobility calculated from EPC matrix element is closed to that from the longitudinal acoustic phonon DPT. In this study, we have also investigated the effect of polarization properties in 2D InSe on electron mobility. At 300 K, the electron mobility for including Fröhlich interaction is reduced to [Formula: see text] and [Formula: see text] [Formula: see text]. Therefore, the electron mobility for InSe is controlled by the scattering from polar phonons. The mobility can be increased to [Formula: see text] and [Formula: see text] [Formula: see text] under 4% biaxial strain. This result is compared with the experiment, and some disagreements are explained.
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Affiliation(s)
- Li-Bin Shi
- School of Mathematics and Physics, Bohai University, Liaoning Jinzhou 121013, People's Republic of China
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74
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Xiao K, Yan T, Cui X. Dipole Orientation Shift of Ga 2Se 2 by Quantum Confinement. ACS NANO 2020; 14:1027-1032. [PMID: 31799830 DOI: 10.1021/acsnano.9b08524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
In the family of III-VI monochalcogenides M2X2 (M = gallium, indium; X = sulfur, selenide, etc.), the interlayer interaction and the electronic band edges share the contribution of the same chalcogenide atomic orbits. This makes quantum confinement and interlayer interaction play a subtle role in two-dimensional (2D) monochalcogenides crystals. In this report, we study the direction-resolved photoluminescence of 2D Ga2Se2 at various thicknesses. We observe that the in-plane dipole radiation survives, but out-of-plane dipole radiation fades at 2D limits.
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Affiliation(s)
- Ke Xiao
- Department of Physics , University of Hong Kong , Hong Kong , China
| | - Tengfei Yan
- Department of Physics , University of Hong Kong , Hong Kong , China
| | - Xiaodong Cui
- Department of Physics , University of Hong Kong , Hong Kong , China
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75
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Zultak J, Magorrian SJ, Koperski M, Garner A, Hamer MJ, Tóvári E, Novoselov KS, Zhukov AA, Zou Y, Wilson NR, Haigh SJ, Kretinin AV, Fal'ko VI, Gorbachev R. Ultra-thin van der Waals crystals as semiconductor quantum wells. Nat Commun 2020; 11:125. [PMID: 31913279 PMCID: PMC6949292 DOI: 10.1038/s41467-019-13893-w] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 11/28/2019] [Indexed: 11/09/2022] Open
Abstract
Control over the quantization of electrons in quantum wells is at the heart of the functioning of modern advanced electronics; high electron mobility transistors, semiconductor and Capasso terahertz lasers, and many others. However, this avenue has not been explored in the case of 2D materials. Here we apply this concept to van der Waals heterostructures using the thickness of exfoliated crystals to control the quantum well dimensions in few-layer semiconductor InSe. This approach realizes precise control over the energy of the subbands and their uniformity guarantees extremely high quality electronic transport in these systems. Using tunnelling and light emitting devices, we reveal the full subband structure by studying resonance features in the tunnelling current, photoabsorption and light emission spectra. In the future, these systems could enable development of elementary blocks for atomically thin infrared and THz light sources based on intersubband optical transitions in few-layer van der Waals materials.
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Affiliation(s)
- Johanna Zultak
- Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Samuel J Magorrian
- Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Maciej Koperski
- Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Alistair Garner
- Department of Materials, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Matthew J Hamer
- Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Endre Tóvári
- Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Kostya S Novoselov
- Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Alexander A Zhukov
- Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester, M13 9PL, UK.,National Graphene Institute, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Yichao Zou
- National Graphene Institute, University of Manchester, Oxford Road, Manchester, M13 9PL, UK.,Department of Materials, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Neil R Wilson
- Department of Physics, University of Warwick, Coventry, CV4 7AL, UK
| | - Sarah J Haigh
- National Graphene Institute, University of Manchester, Oxford Road, Manchester, M13 9PL, UK.,Department of Materials, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Andrey V Kretinin
- National Graphene Institute, University of Manchester, Oxford Road, Manchester, M13 9PL, UK.,Department of Materials, University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Vladimir I Fal'ko
- Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester, M13 9PL, UK. .,National Graphene Institute, University of Manchester, Oxford Road, Manchester, M13 9PL, UK. .,Henry Royce Institute for Advanced Materials, University of Manchester, Oxford Road, Manchester, M13 9PL, UK.
| | - Roman Gorbachev
- Department of Physics and Astronomy, University of Manchester, Oxford Road, Manchester, M13 9PL, UK. .,National Graphene Institute, University of Manchester, Oxford Road, Manchester, M13 9PL, UK. .,Henry Royce Institute for Advanced Materials, University of Manchester, Oxford Road, Manchester, M13 9PL, UK.
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76
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Li YH, Zhang ZH, Fan ZQ, Zhou RL. Magneto-electronic properties, carrier mobility and strain effects of InSe nanoribbon. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:015303. [PMID: 31499486 DOI: 10.1088/1361-648x/ab4293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The monolayer InSe has been successfully fabricated recently and studied intensely. Here, we investigate the geometrical stability and various physical properties such as electronic and magnetic feature, carrier mobility and strain effects for InSe nanoribbons. Our calculations show that armchair nanoribbons, regardless of the bare-edged or H-saturated ones, are semiconductors with an indirect bandgaps, but the bandgap size is increased greatly by H-saturation. Their electron mobility is predicted to be moderately large (from ~102 to ~103 cm2 V-1 s-1) with the holes being less mobile for wider ribbons, and the carrier polarity phenomenon becomes more prominently for H-saturation. The zigzag InSe nanoribbons are found to be magnetic metals with a bigger magnetic moment and the ferromagnetic ground state at the single edge. The magnetism stems from unpaired electrons at the In-rich edge. More interestingly, it is found that the externally applied mechanical strain can effectively tune the spin polarization efficiency at the Fermi level to two stepwise stages, suggesting that the strain can act as a tool for developing a mechanical switch to control spin-polarized transport under lower bias. The detailed analysis suggests that this strain-tuning mechanism can be attributed to the ionic and covalent bond-configuration competition due to the strain-induced bond-length alterations, which leads to the unpaired electron redistribution in magnetic atoms or vanishing.
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Affiliation(s)
- Y H Li
- Hunan Provincial Key Laboratory of Flexible Electronic Materials Genome Engineering, Changsha University of Science and Technology, Changsha 410114, People's Republic of China
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77
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Sun M, Wang W, Zhao Q, Gan X, Sun Y, Jie W, Wang T. ε-InSe single crystals grown by a horizontal gradient freeze method. CrystEngComm 2020. [DOI: 10.1039/d0ce01271h] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Indium selenide (InSe) single crystals have been considered as promising candidates for future optical, electrical, and optoelectronic device applications.
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Affiliation(s)
- Maojun Sun
- State Key Laboratory of Solidification Processing
- Northwestern Polytechnical University
- Xi'an
- P. R. China
- Key Laboratory of Radiation Detection Materials and Devices
| | - Wei Wang
- State Key Laboratory of Solidification Processing
- Northwestern Polytechnical University
- Xi'an
- P. R. China
- Key Laboratory of Radiation Detection Materials and Devices
| | - Qinghua Zhao
- State Key Laboratory of Solidification Processing
- Northwestern Polytechnical University
- Xi'an
- P. R. China
- Key Laboratory of Radiation Detection Materials and Devices
| | - Xuetao Gan
- School of Physical Science and Technology
- Northwestern Polytechnical University
- Xi'an
- P. R. China
| | - Yuanhui Sun
- Department of Chemistry and Biochemistry
- California State University Northridge
- Northridge
- USA
| | - Wanqi Jie
- State Key Laboratory of Solidification Processing
- Northwestern Polytechnical University
- Xi'an
- P. R. China
- Key Laboratory of Radiation Detection Materials and Devices
| | - Tao Wang
- State Key Laboratory of Solidification Processing
- Northwestern Polytechnical University
- Xi'an
- P. R. China
- Key Laboratory of Radiation Detection Materials and Devices
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78
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Guo S, Tan W, Qiu J, Du J, Yang Z, Wang X. Classification of Spatially Confined Reactions and the Electrochemical Applications of Molybdenum-Based Nanocomposites. Aust J Chem 2020. [DOI: 10.1071/ch19505] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
As a popular material synthesis method, spatially confined reactions have been gradually recognised for their excellent performance in the field of current materials synthesis. In recent years, molybdenum-based catalysts have gradually gained recognition due to high natural reserves of Mo, its low cost, and many other advantages, and they have wide applications in the area of functional materials, especially in topical areas such as batteries and electrocatalysts. In this context, spatially confined reactions have become widely to obtain various types of molybdenum-based electrode materials and electrocatalysts which result in an excellent morphology, structure, and performance. In this review, the concept of a spatially confined reaction system and the electrochemical application (electrode materials and electrocatalyst) of molybdenum-based materials synthesised in this way are comprehensively discussed. The current problems and future development and application of molybdenum-based materials are also discussed in this review.
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79
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Pan H, Cao L, Chu H, Wang Y, Zhao S, Li Y, Qi N, Sun Z, Jiang X, Wang R, Zhang H, Li D. Broadband Nonlinear Optical Response of InSe Nanosheets for the Pulse Generation From 1 to 2 μm. ACS APPLIED MATERIALS & INTERFACES 2019; 11:48281-48289. [PMID: 31834767 DOI: 10.1021/acsami.9b18632] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Few-layered InSe nanosheets were fabricated by the simple liquid-phase exfoliation method. The morphology and crystal structure features of InSe nanosheet sample were characterized comprehensively. The photoluminescence (PL) spectrum indicated that the liquid-phase exfoliated InSe nanosheets contained variously layered nanoflakes, where eight layers nanosheets dominate. In addition, the first-principle simulation was carried out to describe the electron density of states (DOS) and the electronic band structures. Moreover, the few-layered InSe nanosheets performed excellent nonlinear absorption properties in a broad spectral band. As an application, the stable passively Q-switched (PQS) lasers with few-layered InSe nanosheets saturable absorbers (SAs) were realized with the operating wavelengths at 1.06, 1.34, and 1.91 μm. The shortest pulse durations were 599, 520, and 210 ns, respectively. Our results confirmed that the few-layered InSe nanosheets could be an excellent candidate for pulsed lasers in wide spectral bands.
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Affiliation(s)
- Han Pan
- School of Information Science and Engineering , Shandong University , Qingdao 266237 , China
| | - Lihua Cao
- School of Information Science and Engineering , Shandong University , Qingdao 266237 , China
| | - Hongwei Chu
- School of Information Science and Engineering , Shandong University , Qingdao 266237 , China
| | - Yunzheng Wang
- Collaborative Innovation Center for Optoelectronic Science & Technology, International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology of Ministry of Education, College of Physics and Optoelectronic Engineering , Shenzhen University , Shenzhen 518060 , China
| | - Shengzhi Zhao
- School of Information Science and Engineering , Shandong University , Qingdao 266237 , China
| | - Ying Li
- Key Laboratory of Colloid and Interface Chemistry of State Education Ministry, School of Chemistry and Chemical Engineering , Shandong University , Jinan 250100 , China
| | - Na Qi
- Key Laboratory of Colloid and Interface Chemistry of State Education Ministry, School of Chemistry and Chemical Engineering , Shandong University , Jinan 250100 , China
| | - Zhenlu Sun
- School of Information Science and Engineering , Shandong University , Qingdao 266237 , China
| | - Xiantao Jiang
- Collaborative Innovation Center for Optoelectronic Science & Technology, International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology of Ministry of Education, College of Physics and Optoelectronic Engineering , Shenzhen University , Shenzhen 518060 , China
| | - Rui Wang
- Department of Electronic Engineering , Xiamen University , Xiamen 361005 , China
| | - Han Zhang
- Collaborative Innovation Center for Optoelectronic Science & Technology, International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology of Ministry of Education, College of Physics and Optoelectronic Engineering , Shenzhen University , Shenzhen 518060 , China
| | - Dechun Li
- School of Information Science and Engineering , Shandong University , Qingdao 266237 , China
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80
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Chen T, Lu Y, Sheng Y, Shu Y, Li X, Chang RJ, Bhaskaran H, Warner JH. Ultrathin All-2D Lateral Graphene/GaS/Graphene UV Photodetectors by Direct CVD Growth. ACS APPLIED MATERIALS & INTERFACES 2019; 11:48172-48178. [PMID: 31833364 DOI: 10.1021/acsami.9b11984] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
UV-sensitive lateral all-two-dimensional (2D) photodetecting devices are produced by growing the large band gap layered GaS between graphene electrode pairs directly using chemical vapor deposition methods. The use of prepatterned graphene electrode pairs on the Si wafer enables more than 200 devices to be fabricated simultaneously. We show that the surface chemistry of the substrate during GaS leads to selective growth in graphene gaps, forming the lateral heterostructures, rather than on the surface of graphene. The graphene/GaS/graphene lateral photodetecting devices are demonstrated to be sensitive to UV light only, with no measurable response to visible light. Furthermore, we demonstrate UV-band discrimination in photosensing, with measured photocurrents only produced for middle-UV and not for near-UV wavelength regions. The detection limit could reach down to 2.61 μW/cm2 with a photoresponsivity as high as 11.7 A/W and a photo gain of 53.7 under 270 nm excitation. Gate-dependent modulation of the photocurrent is also demonstrated. The photodetectors exhibit long-term stability and reproducible ON-OFF switching behavior, with a response time lower than 60 ms. These results provide insights into how ultrathin UV sensing devices can be created using only 2D materials by exploiting large band gap 2D semiconductors such as GaS.
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Affiliation(s)
- Tongxin Chen
- Department of Materials , University of Oxford , Parks Road , Oxford OX1 3PH , United Kingdom
| | - Yang Lu
- Department of Materials , University of Oxford , Parks Road , Oxford OX1 3PH , United Kingdom
| | - Yuewen Sheng
- Department of Materials , University of Oxford , Parks Road , Oxford OX1 3PH , United Kingdom
| | - Yu Shu
- Department of Materials , University of Oxford , Parks Road , Oxford OX1 3PH , United Kingdom
| | - Xuan Li
- Department of Materials , University of Oxford , Parks Road , Oxford OX1 3PH , United Kingdom
| | - Ren-Jie Chang
- Department of Materials , University of Oxford , Parks Road , Oxford OX1 3PH , United Kingdom
| | - Harish Bhaskaran
- Department of Materials , University of Oxford , Parks Road , Oxford OX1 3PH , United Kingdom
| | - Jamie H Warner
- Department of Materials , University of Oxford , Parks Road , Oxford OX1 3PH , United Kingdom
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81
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Liu X, Ren JC, Shen T, Li S, Liu W. Lateral InSe p-n Junction Formed by Partial Doping for Use in Ultrathin Flexible Solar Cells. J Phys Chem Lett 2019; 10:7712-7718. [PMID: 31769691 DOI: 10.1021/acs.jpclett.9b03184] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Two-dimensional InSe possesses good electrical conductivity, intrinsic and structural flexibility, high chemical stability, and a tunable band gap, enabling it to be a promising candidate for flexible and wearable solar cells. Here we construct a lateral p-n junction by partially doping molybdenum trioxide (MoO3) at the surface of the InSe monolayer. Our density functional theory calculations reveal that the strong hybridization between MoO3 and InSe induces a lateral built-in electric field in the partially doped substrate and promotes the effective separation of carriers. Under a large range of external stains, the doped InSe can maintain the direct band gap, and the lateral structure device exhibits power conversion efficiencies over 5% and high carrier mobility around 1000 cm2 V-1 s-1. In particular, a power conversion efficiency of 20.7% can be achieved with 10% compressive strain. The partially doped InSe monolayer is expected to be used as an ultrathin flexible solar cell.
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Affiliation(s)
- Xinyi Liu
- Nano and Heterogeneous Materials Center, School of Materials Science and Engineering , Nanjing University of Science and Technology , Nanjing 210094 , China
| | - Ji-Chang Ren
- Nano and Heterogeneous Materials Center, School of Materials Science and Engineering , Nanjing University of Science and Technology , Nanjing 210094 , China
| | - Tao Shen
- Nano and Heterogeneous Materials Center, School of Materials Science and Engineering , Nanjing University of Science and Technology , Nanjing 210094 , China
| | - Shuang Li
- Nano and Heterogeneous Materials Center, School of Materials Science and Engineering , Nanjing University of Science and Technology , Nanjing 210094 , China
| | - Wei Liu
- Nano and Heterogeneous Materials Center, School of Materials Science and Engineering , Nanjing University of Science and Technology , Nanjing 210094 , China
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82
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Arora H, Jung Y, Venanzi T, Watanabe K, Taniguchi T, Hübner R, Schneider H, Helm M, Hone JC, Erbe A. Effective Hexagonal Boron Nitride Passivation of Few-Layered InSe and GaSe to Enhance Their Electronic and Optical Properties. ACS APPLIED MATERIALS & INTERFACES 2019; 11:43480-43487. [PMID: 31651146 DOI: 10.1021/acsami.9b13442] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Indium selenide (InSe) and gallium selenide (GaSe), members of the III-VI chalcogenide family, are emerging two-dimensional (2D) semiconductors with appealing electronic properties. However, their devices are still lagging behind because of their sensitivity to air and device fabrication processes which induce structural damage and hamper their intrinsic properties. Thus, in order to obtain high-performance and stable devices, effective passivation of these air-sensitive materials is strongly required. Here, we demonstrate a hexagonal boron nitride (hBN)-based encapsulation technique, where 2D layers of InSe and GaSe are covered entirely between two layers of hBN. To fabricate devices out of fully encapsulated 2D layers, we employ the lithography-free via-contacting scheme. We find that hBN acts as an excellent encapsulant and a near-ideal substrate for InSe and GaSe by passivating them from the environment and isolating them from the charge disorder at the SiO2 surface. As a result, the encapsulated InSe devices are of high quality and ambient-stable for a long time and show an improved two-terminal mobility of 30-120 cm2 V-1 s-1 as compared to mere ∼1 cm2 V-1 s-1 for unencapsulated devices. On employing this technique to GaSe, we obtain a strong and reproducible photoresponse. In contrast to previous studies, where either good performance or long-term stability was achieved, we demonstrate a combination of both in our devices. This work thus provides a systematic study of fully encapsulated devices based on InSe and GaSe, which has not been reported until now. We believe that this technique can open ways for fundamental studies as well as toward the integration of these materials in technological applications.
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Affiliation(s)
- Himani Arora
- Helmholtz-Zentrum Dresden-Rossendorf , 01328 Dresden , Saxony , Germany
- Technische Universität Dresden , 01062 Dresden , Saxony , Germany
| | - Younghun Jung
- Department of Mechanical Engineering , Columbia University , 10027 New York , New York , United States
| | - Tommaso Venanzi
- Helmholtz-Zentrum Dresden-Rossendorf , 01328 Dresden , Saxony , Germany
- Technische Universität Dresden , 01062 Dresden , Saxony , Germany
| | - Kenji Watanabe
- National Institute for Materials Science , 1-1 Namiki , 305-0044 Tsukuba , Ibaraki , Japan
| | - Takashi Taniguchi
- National Institute for Materials Science , 1-1 Namiki , 305-0044 Tsukuba , Ibaraki , Japan
| | - René Hübner
- Helmholtz-Zentrum Dresden-Rossendorf , 01328 Dresden , Saxony , Germany
| | - Harald Schneider
- Helmholtz-Zentrum Dresden-Rossendorf , 01328 Dresden , Saxony , Germany
| | - Manfred Helm
- Helmholtz-Zentrum Dresden-Rossendorf , 01328 Dresden , Saxony , Germany
- Technische Universität Dresden , 01062 Dresden , Saxony , Germany
| | - James C Hone
- Department of Mechanical Engineering , Columbia University , 10027 New York , New York , United States
| | - Artur Erbe
- Helmholtz-Zentrum Dresden-Rossendorf , 01328 Dresden , Saxony , Germany
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83
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Wang X, Cui A, Chen F, Xu L, Hu Z, Jiang K, Shang L, Chu J. Probing Effective Out-of-Plane Piezoelectricity in van der Waals Layered Materials Induced by Flexoelectricity. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2019; 15:e1903106. [PMID: 31550085 DOI: 10.1002/smll.201903106] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 08/26/2019] [Indexed: 06/10/2023]
Abstract
Many van der Waals layered 2D materials, such as h-BN, transition metal dichalcogenides (TMDs), and group-III monochalcogenides, have been predicted to possess piezoelectric and mechanically flexible natures, which greatly motivates potential applications in piezotronic devices and nanogenerators. However, only intrinsic in-plane piezoelectricity exists in these 2D materials and the piezoelectric effect is confined in odd-layers of TMDs. The present work is intent on combining the free-standing design and piezoresponse force microscopy techniques to obtain and directly quantify the effective out-of-plane electromechanical coupling induced by strain gradient on atomically thin MoS2 and InSe flakes. Conspicuous piezoresponse and the measured piezoelectric coefficient with respect to the number of layers or thickness are systematically illustrated for both MoS2 and InSe flakes. Note that the promising effective piezoelectric coefficient (deff 33 ) of about 21.9 pm V-1 is observed on few-layered InSe. The out-of-plane piezoresponse arises from the net dipole moment along the normal direction of the curvature membrane induced by strain gradient. This work not only provides a feasible and flexible method to acquire and quantify the out-of-plane electromechanical coupling on van der Waals layered materials, but also paves the way to understand and tune the flexoelectric effect of 2D systems.
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Affiliation(s)
- Xiang Wang
- Technical Center for Multifunctional Magneto-Optical Spectroscopy (Shanghai), Department of Electronic Engineering, East China Normal University, Shanghai, 200241, China
| | - Anyang Cui
- Technical Center for Multifunctional Magneto-Optical Spectroscopy (Shanghai), Department of Electronic Engineering, East China Normal University, Shanghai, 200241, China
| | - Fangfang Chen
- Technical Center for Multifunctional Magneto-Optical Spectroscopy (Shanghai), Department of Electronic Engineering, East China Normal University, Shanghai, 200241, China
| | - Liping Xu
- Technical Center for Multifunctional Magneto-Optical Spectroscopy (Shanghai), Department of Electronic Engineering, East China Normal University, Shanghai, 200241, China
| | - Zhigao Hu
- Technical Center for Multifunctional Magneto-Optical Spectroscopy (Shanghai), Department of Electronic Engineering, East China Normal University, Shanghai, 200241, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, 030006, Shanxi, China
- Shanghai Institute of Intelligent Electronics and Systems, Fudan University, Shanghai, 200433, China
| | - Kai Jiang
- Technical Center for Multifunctional Magneto-Optical Spectroscopy (Shanghai), Department of Electronic Engineering, East China Normal University, Shanghai, 200241, China
| | - Liyan Shang
- Technical Center for Multifunctional Magneto-Optical Spectroscopy (Shanghai), Department of Electronic Engineering, East China Normal University, Shanghai, 200241, China
| | - Junhao Chu
- Technical Center for Multifunctional Magneto-Optical Spectroscopy (Shanghai), Department of Electronic Engineering, East China Normal University, Shanghai, 200241, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, 030006, Shanxi, China
- Shanghai Institute of Intelligent Electronics and Systems, Fudan University, Shanghai, 200433, China
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84
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Chen X, Huang Y, Liu J, Yuan H, Chen H. Thermoelectric Performance of Two-Dimensional AlX (X = S, Se, Te): A First-Principles-Based Transport Study. ACS OMEGA 2019; 4:17773-17781. [PMID: 31681883 PMCID: PMC6822128 DOI: 10.1021/acsomega.9b02235] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 10/02/2019] [Indexed: 06/01/2023]
Abstract
By using the first-principles calculations in combination with the Boltzmann transport theory, we systematically study the thermoelectric properties of AlX (X = S, Se, Te) monolayers as indirect gap semiconductors. The unique electronic density of states, which consists of a rather sharp peak at the valence band maxima and an almost constant band at the conduction band minima, makes AlX (X = S, Se, Te) monolayers excellent thermoelectric materials. The optimized power factors at room temperature are 22.59, 62.59, and 6.79 mW m-1 K-2 under reasonable electronic concentration for AlS, AlSe, and AlTe monolayers, respectively. The figure of merit (zT) increases with temperature and the optimized zT values of 0.52, 0.59, and 0.26 at room temperature are achieved under moderate electronic concentration for AlS, AlSe, and AlTe monolayers, respectively, indicating that two-dimensional layered AlX (X = S, Se, Te) semiconductors, especially AlSe, can be potential candidate matrices for high-performance thermoelectric nanocomposites.
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Affiliation(s)
- Xiaorui Chen
- School of Physical Science and Technology, Southwest University, Chongqing 400715, China
| | - Yuhong Huang
- School of Physical Science and Technology, Southwest University, Chongqing 400715, China
| | - Jing Liu
- School of Physical Science and Technology, Southwest University, Chongqing 400715, China
| | - Hongkuan Yuan
- School of Physical Science and Technology, Southwest University, Chongqing 400715, China
| | - Hong Chen
- School of Physical Science and Technology, Southwest University, Chongqing 400715, China
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85
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Lugovskoi AV, Katsnelson MI, Rudenko AN. Strong Electron-Phonon Coupling and its Influence on the Transport and Optical Properties of Hole-Doped Single-Layer InSe. PHYSICAL REVIEW LETTERS 2019; 123:176401. [PMID: 31702262 DOI: 10.1103/physrevlett.123.176401] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Indexed: 06/10/2023]
Abstract
We show that hole states in recently discovered single-layer InSe are strongly renormalized by the coupling with acoustic phonons. The coupling is enhanced significantly at moderate hole doping (∼10^{13} cm^{-2}) due to hexagonal warping of the Fermi surface. While the system remains dynamically stable, its electron-phonon spectral function exhibits sharp low-energy resonances, leading to the formation of satellite quasiparticle states near the Fermi energy. Such many-body renormalization is predicted to have two important consequences. First, it significantly suppresses charge carrier mobility reaching ∼1 cm^{2} V^{-1} s^{-1} at 100 K in a freestanding sample. Second, it gives rise to unusual temperature-dependent optical excitations in the midinfrared region. Relatively small charge carrier concentrations and realistic temperatures suggest that these excitations may be observed experimentally.
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Affiliation(s)
- A V Lugovskoi
- Institute for Molecules and Materials, Radboud University, Heijendaalseweg 135, NL-6525 AJ Nijmegen, Netherlands
| | - M I Katsnelson
- Institute for Molecules and Materials, Radboud University, Heijendaalseweg 135, NL-6525 AJ Nijmegen, Netherlands
- Theoretical Physics and Applied Mathematics Department, Ural Federal University, 620002 Ekaterinburg, Russia
| | - A N Rudenko
- Institute for Molecules and Materials, Radboud University, Heijendaalseweg 135, NL-6525 AJ Nijmegen, Netherlands
- Theoretical Physics and Applied Mathematics Department, Ural Federal University, 620002 Ekaterinburg, Russia
- School of Physics and Technology, Wuhan University, Wuhan 430072, China
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86
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Greener JDG, de Lima Savi E, Akimov AV, Raetz S, Kudrynskyi Z, Kovalyuk ZD, Chigarev N, Kent A, Patané A, Gusev V. High-Frequency Elastic Coupling at the Interface of van der Waals Nanolayers Imaged by Picosecond Ultrasonics. ACS NANO 2019; 13:11530-11537. [PMID: 31487450 DOI: 10.1021/acsnano.9b05052] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Although the topography of van de Waals (vdW) layers and heterostructures can be imaged by scanning probe microscopy, high-frequency interface elastic properties are more difficult to assess. These can influence the stability, reliability, and performance of electronic devices that require uniform layers and interfaces. Here, we use picosecond ultrasonics to image these properties in vdW layers and heterostructures based on well-known exfoliable materials, i.e., InSe, hBN, and graphene. We reveal a strong, uniform elastic coupling between vdW layers over a wide range of frequencies of up to tens of gigahertz (GHz) and in-plane areas of 100 μm2. In contrast, the vdW layers can be weakly coupled to their supporting substrate, behaving effectively as free-standing membranes. Our data and analysis demonstrate that picosecond ultrasonics offers opportunities to probe the high-frequency elastic coupling of vdW nanolayers and image both "perfect" and "broken" interfaces between different materials over a wide frequency range, as required for future scientific and technological developments.
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Affiliation(s)
- Jake D G Greener
- School of Physics and Astronomy , The University Nottingham , Nottingham NG7 2RD , U.K
| | - Elton de Lima Savi
- Laboratoire d'Acoustique de l'Université du Mans, LAUM - UMR 6613 CNRS , Le Mans Université , Avenue Olivier Messiaen , 72085 Le Mans Cedex 9 , France
| | - Andrey V Akimov
- School of Physics and Astronomy , The University Nottingham , Nottingham NG7 2RD , U.K
| | - Samuel Raetz
- Laboratoire d'Acoustique de l'Université du Mans, LAUM - UMR 6613 CNRS , Le Mans Université , Avenue Olivier Messiaen , 72085 Le Mans Cedex 9 , France
| | - Zakhar Kudrynskyi
- School of Physics and Astronomy , The University Nottingham , Nottingham NG7 2RD , U.K
| | - Zakhar D Kovalyuk
- Chernivtsi Branch of Frantsevich Institute for Problems of Materials Science, the National Academy of Sciences of Ukraine 5 , I. Vilde Street , Chernivtsi , 58001 , Ukraine
| | - Nikolay Chigarev
- Laboratoire d'Acoustique de l'Université du Mans, LAUM - UMR 6613 CNRS , Le Mans Université , Avenue Olivier Messiaen , 72085 Le Mans Cedex 9 , France
| | - Anthony Kent
- School of Physics and Astronomy , The University Nottingham , Nottingham NG7 2RD , U.K
| | - Amalia Patané
- School of Physics and Astronomy , The University Nottingham , Nottingham NG7 2RD , U.K
| | - Vitalyi Gusev
- Laboratoire d'Acoustique de l'Université du Mans, LAUM - UMR 6613 CNRS , Le Mans Université , Avenue Olivier Messiaen , 72085 Le Mans Cedex 9 , France
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87
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Taniguchi T, Li S, Nurdiwijayanto L, Kobayashi Y, Saito T, Miyata Y, Obata S, Saiki K, Yokoi H, Watanabe K, Taniguchi T, Tsukagoshi K, Ebina Y, Sasaki T, Osada M. Tunable Chemical Coupling in Two-Dimensional van der Waals Electrostatic Heterostructures. ACS NANO 2019; 13:11214-11223. [PMID: 31580052 DOI: 10.1021/acsnano.9b04256] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Heterostructures of two-dimensional (2D) atomic crystals provide fascinating molecular-scale design elements for emergent physical phenomena and functional materials, as integrating distinct monolayers into vertical heterostructures can afford coupling between disparate properties. However, the available examples have been limited to either van der Waals (vdW) or electrostatic (ES) heterostructures that are solely composed of noncharged and charged monolayers, respectively. Here, we propose a "vdW-ES heterostructure" chemical design in which charge-neutral and charged monolayer-building blocks with highly disparate chemical and physical properties are conjugated vertically through asymmetrically charged interfaces. We demonstrate vdW-ES heteroassembly of semiconducting MoS2 and dielectric Ca2Nb3O10- (CNO) monolayers using an amphipathic molecular starch, resulting in the emergence of trion luminescence observed at the lowest energy among MoS2-related materials, probably due to interfacial confinement effects given by vdW-ES dual interactions. In addition, interface engineering leads to tailored exciton of the vdW/ES heterostructures owing to the pronounced dielectric proximity effects, bringing an intriguing interlayer chemistry to modify 2D materials. Furthermore, the current approach was successfully extended to create a graphene/CNO heterostructure, which verifies the versatility of the preparative method.
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Affiliation(s)
- Takaaki Taniguchi
- World Premier International Center for Materials Nanoarchitectonics (WPI-MANA) , National Institute for Materials Science(NIMS) , 1-1 Namiki , Tsukuba , Ibaraki 305-0044 , Japan
| | - Shisheng Li
- World Premier International Center for Materials Nanoarchitectonics (WPI-MANA) , National Institute for Materials Science(NIMS) , 1-1 Namiki , Tsukuba , Ibaraki 305-0044 , Japan
| | - Leanddas Nurdiwijayanto
- World Premier International Center for Materials Nanoarchitectonics (WPI-MANA) , National Institute for Materials Science(NIMS) , 1-1 Namiki , Tsukuba , Ibaraki 305-0044 , Japan
| | - Yu Kobayashi
- Department of Physics , Tokyo Metropolitan University , Hachioji , Tokyo 192-0397 , Japan
| | - Tetsuki Saito
- Department of Physics , Tokyo Metropolitan University , Hachioji , Tokyo 192-0397 , Japan
| | - Yasumitsu Miyata
- Department of Physics , Tokyo Metropolitan University , Hachioji , Tokyo 192-0397 , Japan
| | - Seiji Obata
- Department of Complexity Science and Engineering , Graduate School of Frontier Sciences, The University of Tokyo , Kashiwa , Chiba 277-8561 , Japan
| | - Koichiro Saiki
- Department of Complexity Science and Engineering , Graduate School of Frontier Sciences, The University of Tokyo , Kashiwa , Chiba 277-8561 , Japan
| | - Hiroyuki Yokoi
- Faculty of Advanced Science and Technology , Kumamoto University , Kumamoto 860-8555 , Japan
| | - Kenji Watanabe
- Research Center for Functional Materials , National Institute for Materials Science(NIMS) , 1-1 Namiki , Tsukuba , Ibaraki 305-0044 , Japan
| | - Takashi Taniguchi
- Research Center for Functional Materials , National Institute for Materials Science(NIMS) , 1-1 Namiki , Tsukuba , Ibaraki 305-0044 , Japan
| | - Kazuhito Tsukagoshi
- World Premier International Center for Materials Nanoarchitectonics (WPI-MANA) , National Institute for Materials Science(NIMS) , 1-1 Namiki , Tsukuba , Ibaraki 305-0044 , Japan
| | - Yasuo Ebina
- World Premier International Center for Materials Nanoarchitectonics (WPI-MANA) , National Institute for Materials Science(NIMS) , 1-1 Namiki , Tsukuba , Ibaraki 305-0044 , Japan
| | - Takayoshi Sasaki
- World Premier International Center for Materials Nanoarchitectonics (WPI-MANA) , National Institute for Materials Science(NIMS) , 1-1 Namiki , Tsukuba , Ibaraki 305-0044 , Japan
| | - Minoru Osada
- World Premier International Center for Materials Nanoarchitectonics (WPI-MANA) , National Institute for Materials Science(NIMS) , 1-1 Namiki , Tsukuba , Ibaraki 305-0044 , Japan
- Institute of Materials and Systems for Sustainability , Nagoya University , Furocho, Chikusa-ku, Nagoya 464-8603 , Japan
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88
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Xiao XB, Ye Q, Liu ZF, Wu QP, Li Y, Ai GP. Electric Field Controlled Indirect-Direct-Indirect Band Gap Transition in Monolayer InSe. NANOSCALE RESEARCH LETTERS 2019; 14:322. [PMID: 31617005 PMCID: PMC6794337 DOI: 10.1186/s11671-019-3162-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 09/26/2019] [Indexed: 06/10/2023]
Abstract
Electronic structures of monolayer InSe with a perpendicular electric field are investigated. Indirect-direct-indirect band gap transition is found in monolayer InSe as the electric field strength is increased continuously. Meanwhile, the global band gap is suppressed gradually to zero, indicating that semiconductor-metal transformation happens. The underlying mechanisms are revealed by analyzing both the orbital contributions to energy band and evolution of band edges. These findings may not only facilitate our further understanding of electronic characteristics of layered group III-VI semiconductors, but also provide useful guidance for designing optoelectronic devices.
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Affiliation(s)
- Xian-Bo Xiao
- School of Computer Science, Jiangxi University of Traditional Chinese Medicine, Nanchang, 330004, China.
| | - Qian Ye
- School of Computer Science, Jiangxi University of Traditional Chinese Medicine, Nanchang, 330004, China
| | - Zheng-Fang Liu
- School of Science, East China Jiaotong University, Nanchang, 330013, China
| | - Qing-Ping Wu
- School of Science, East China Jiaotong University, Nanchang, 330013, China
| | - Yuan Li
- Department of Physics, Hangzhou Dianzi University, Hangzhou, 310018, China
| | - Guo-Ping Ai
- School of Computer Science, Jiangxi University of Traditional Chinese Medicine, Nanchang, 330004, China
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89
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Chen J, Tan X, Lin P, Sa B, Zhou J, Zhang Y, Wen C, Sun Z. Comprehensive understanding of intrinsic mobility in the monolayers of III-VI group 2D materials. Phys Chem Chem Phys 2019; 21:21898-21907. [PMID: 31552974 DOI: 10.1039/c9cp04407h] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Monolayers of III-VI group two-dimensional (2D) materials MX (M = Ga and In and X = S, Se, and Te) have attracted global interest for potential applications in electronic and photoelectric devices due to their attractive physical and chemical characteristics. However, a comprehensive understanding of the distinguished carrier mobility in MX monolayers is of great importance and not yet clear. Herein, using a Boltzmann transport equation (BTE) solver and first principles calculations, we have precisely revealed that the intrinsic mobility in MX monolayers is significantly limited by phonon scattering. Note that the longitudinal acoustic phonon mode and optic phonon modes and were found predominantly coupled with electrons, which strongly restrained the intrinsic mobility in the MX monolayers. Interestingly, apart from a moderate band gap, the GaSe and GaTe monolayers exhibit high electron mobility exceeding 103 cm2 V-1 s-1 and may serve as outstanding electron transport channels. We believe that our findings will shed light on the design and applications of MX monolayers and 2D materials in nanoscale electronic and photoelectric devices.
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Affiliation(s)
- Jianhui Chen
- Key Laboratory of Eco-materials Advanced Technology, College of Materials Science and Engineering, Fuzhou University, Fuzhou 350108, P. R. China.
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90
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Sreepal V, Yagmurcukardes M, Vasu KS, Kelly DJ, Taylor SFR, Kravets VG, Kudrynskyi Z, Kovalyuk ZD, Patanè A, Grigorenko AN, Haigh SJ, Hardacre C, Eaves L, Sahin H, Geim AK, Peeters FM, Nair RR. Two-Dimensional Covalent Crystals by Chemical Conversion of Thin van der Waals Materials. NANO LETTERS 2019; 19:6475-6481. [PMID: 31426634 PMCID: PMC6814286 DOI: 10.1021/acs.nanolett.9b02700] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 07/30/2019] [Indexed: 06/10/2023]
Abstract
Most of the studied two-dimensional (2D) materials have been obtained by exfoliation of van der Waals crystals. Recently, there has been growing interest in fabricating synthetic 2D crystals which have no layered bulk analogues. These efforts have been focused mainly on the surface growth of molecules in high vacuum. Here, we report an approach to making 2D crystals of covalent solids by chemical conversion of van der Waals layers. As an example, we used 2D indium selenide (InSe) obtained by exfoliation and converted it by direct fluorination into indium fluoride (InF3), which has a nonlayered, rhombohedral structure and therefore cannot possibly be obtained by exfoliation. The conversion of InSe into InF3 is found to be feasible for thicknesses down to three layers of InSe, and the obtained stable InF3 layers are doped with selenium. We study this new 2D material by optical, electron transport, and Raman measurements and show that it is a semiconductor with a direct bandgap of 2.2 eV, exhibiting high optical transparency across the visible and infrared spectral ranges. We also demonstrate the scalability of our approach by chemical conversion of large-area, thin InSe laminates obtained by liquid exfoliation, into InF3 films. The concept of chemical conversion of cleavable thin van der Waals crystals into covalently bonded noncleavable ones opens exciting prospects for synthesizing a wide variety of novel atomically thin covalent crystals.
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Affiliation(s)
- Vishnu Sreepal
- National Graphene Institute and School of Chemical Engineering and Analytical
Science, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Mehmet Yagmurcukardes
- Department
of Physics, University of Antwerpen, Groenenborgerlaan 171, B-2020 Antwerpen, Belgium
| | - Kalangi S. Vasu
- National Graphene Institute and School of Chemical Engineering and Analytical
Science, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Daniel J. Kelly
- School of Materials and School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Sarah F. R. Taylor
- National Graphene Institute and School of Chemical Engineering and Analytical
Science, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Vasyl G. Kravets
- School of Materials and School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Zakhar Kudrynskyi
- School of
Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Zakhar D. Kovalyuk
- Institute
for Problems of Materials Science, The National
Academy of Sciences of Ukraine, Chernivtsi Branch, Chernivtsi 58001, Ukraine
| | - Amalia Patanè
- School of
Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Alexander N. Grigorenko
- School of Materials and School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Sarah J. Haigh
- National Graphene Institute and School of Chemical Engineering and Analytical
Science, University of Manchester, Manchester M13 9PL, United Kingdom
- School of Materials and School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Christopher Hardacre
- National Graphene Institute and School of Chemical Engineering and Analytical
Science, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Laurence Eaves
- School of Materials and School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom
- School of
Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Hasan Sahin
- Department
of Photonics, Izmir Institute of Technology, 35430, Izmir, Turkey
| | - Andre K. Geim
- School of Materials and School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Francois M. Peeters
- Department
of Physics, University of Antwerpen, Groenenborgerlaan 171, B-2020 Antwerpen, Belgium
| | - Rahul R. Nair
- National Graphene Institute and School of Chemical Engineering and Analytical
Science, University of Manchester, Manchester M13 9PL, United Kingdom
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91
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Brotons-Gisbert M, Proux R, Picard R, Andres-Penares D, Branny A, Molina-Sánchez A, Sánchez-Royo JF, Gerardot BD. Out-of-plane orientation of luminescent excitons in two-dimensional indium selenide. Nat Commun 2019; 10:3913. [PMID: 31477714 PMCID: PMC6718420 DOI: 10.1038/s41467-019-11920-4] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 07/30/2019] [Indexed: 11/08/2022] Open
Abstract
Van der Waals materials offer a wide range of atomic layers with unique properties that can be easily combined to engineer novel electronic and photonic devices. A missing ingredient of the van der Waals platform is a two-dimensional crystal with naturally occurring out-of-plane luminescent dipole orientation. Here we measure the far-field photoluminescence intensity distribution of bulk InSe and two-dimensional InSe, WSe2 and MoSe2. We demonstrate, with the support of ab-initio calculations, that layered InSe flakes sustain luminescent excitons with an intrinsic out-of-plane orientation, in contrast with the in-plane orientation of dipoles we find in two-dimensional WSe2 and MoSe2 at room-temperature. These results, combined with the high tunability of the optical response and outstanding transport properties, position layered InSe as a promising semiconductor for novel optoelectronic devices, in particular for hybrid integrated photonic chips which exploit the out-of-plane dipole orientation.
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Affiliation(s)
- Mauro Brotons-Gisbert
- Institute of Photonics and Quantum Sciences, SUPA, Heriot-Watt University, Edinburgh, EH14 4AS, UK.
| | - Raphaël Proux
- Institute of Photonics and Quantum Sciences, SUPA, Heriot-Watt University, Edinburgh, EH14 4AS, UK
| | - Raphaël Picard
- Institute of Photonics and Quantum Sciences, SUPA, Heriot-Watt University, Edinburgh, EH14 4AS, UK
| | - Daniel Andres-Penares
- ICMUV, Instituto de Ciencia de Materiales, Universidad de Valencia, P.O. Box 22085, 46071, Valencia, Spain
| | - Artur Branny
- Institute of Photonics and Quantum Sciences, SUPA, Heriot-Watt University, Edinburgh, EH14 4AS, UK
- Department of Applied Physics, Royal Institute of Technology, Stockholm, 106 91, Sweden
| | - Alejandro Molina-Sánchez
- ICMUV, Instituto de Ciencia de Materiales, Universidad de Valencia, P.O. Box 22085, 46071, Valencia, Spain
- International Iberian Nanotechnology Laboratory (INL), Av. Mestre José Veiga, 4715-330, Braga, Portugal
| | - Juan F Sánchez-Royo
- ICMUV, Instituto de Ciencia de Materiales, Universidad de Valencia, P.O. Box 22085, 46071, Valencia, Spain.
| | - Brian D Gerardot
- Institute of Photonics and Quantum Sciences, SUPA, Heriot-Watt University, Edinburgh, EH14 4AS, UK.
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92
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Sutter E, Zhang B, Sun M, Sutter P. Few-Layer to Multilayer Germanium(II) Sulfide: Synthesis, Structure, Stability, and Optoelectronics. ACS NANO 2019; 13:9352-9362. [PMID: 31305983 DOI: 10.1021/acsnano.9b03986] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Among 2D/layered semiconductors, group IV monochalcogenides such as SnS(e) and GeS(e) have attracted attention as phosphorene/black phosphorus analogues with anisotropic structures and predicted unusual properties. In contrast to SnS, for which bottom-up synthesis has been reported, few-layer GeS has been realized primarily via exfoliation from bulk crystals. Here, we report the synthesis of large (up to >20 μm), faceted single crystalline GeS flakes with anisotropic properties using a vapor transport process. In situ electron microscopy is used to identify the thermal stability and sublimation pathways, and demonstrates that the GeS flakes are self-encapsulated in a thin, sulfur-rich amorphous GeSx shell during growth. The shell provides exceptional chemical stability to the layered GeS core. In contrast to exfoliated GeS, which rapidly degrades during exposure to air, the synthesized GeS-GeSx core-shell structures show no signs of chemical attack and remain unchanged in air for extended time periods. Measurements of the optoelectronic properties by photoluminescence spectroscopy show a tunable bandgap due to out-of-plane quantum confinement in flakes with thickness below 100 nm. Cathodoluminescence (CL) spectroscopy with nanoscale excitation provides evidence for interfacial charge transfer due to a type II heterojunction between the crystalline core and amorphous shell. Measurements by locally excited CL yield a minority carrier (electron) diffusion length in the p-type GeS core ldiff = 0.27 μm, on par with diffusion lengths in the highest-quality layered chalcogenide semiconductors.
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Affiliation(s)
- Eli Sutter
- Department of Mechanical and Materials Engineering , University of Nebraska-Lincoln , Lincoln , Nebraska 68588 , United States
| | - Bo Zhang
- Department of Mechanical and Materials Engineering , University of Nebraska-Lincoln , Lincoln , Nebraska 68588 , United States
| | - Muhua Sun
- Department of Mechanical and Materials Engineering , University of Nebraska-Lincoln , Lincoln , Nebraska 68588 , United States
| | - Peter Sutter
- Department of Electrical and Computer Engineering , University of Nebraska-Lincoln , Lincoln , Nebraska 68588 , United States
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93
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Wang Q, Han L, Wu L, Zhang T, Li S, Lu P. Strain Effect on Thermoelectric Performance of InSe Monolayer. NANOSCALE RESEARCH LETTERS 2019; 14:287. [PMID: 31428878 PMCID: PMC6702491 DOI: 10.1186/s11671-019-3113-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 08/01/2019] [Indexed: 06/10/2023]
Abstract
Strain engineering is a practical method to tune and improve the physical characteristics and properties of two-dimensional materials, due to their large stretchability. Tensile strain dependence of electronic, phonon, and thermoelectric properties of InSe monolayer are systematically studied. We demonstrate that the lattice thermal conductivity can be effectively modulated by applying tensile strain. Tensile strain can enhance anharmonic phonon scattering, giving rise to the enhanced phonon scattering rate, reduced phonon group velocity and heat capacity, and therefore lattice thermal conductivity decreases from 25.9 to 13.1 W/mK when the strain of 6% is applied. The enhanced figure of merit indicates that tensile strain is an effective way to improve the thermoelectric performance of InSe monolayer.
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Affiliation(s)
- Qian Wang
- State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing, 100876 China
| | - Lihong Han
- State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing, 100876 China
| | - Liyuan Wu
- State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing, 100876 China
| | - Tao Zhang
- College of Electrical Engineering and Information Technology, Sichuan University, Chengdu, 610065 China
| | - Shanjun Li
- College of Electrical Engineering and Information Technology, Sichuan University, Chengdu, 610065 China
| | - Pengfei Lu
- State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing, 100876 China
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94
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Li Y, Yu C, Gan Y, Kong Y, Jiang P, Zou DF, Li P, Yu XF, Wu R, Zhao H, Gao CF, Li J. Elastic properties and intrinsic strength of two-dimensional InSe flakes. NANOTECHNOLOGY 2019; 30:335703. [PMID: 30995621 DOI: 10.1088/1361-6528/ab1a96] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The mechanical properties of two-dimensional (2D) materials are critical for their applications in functional devices as well as for strain engineering. Here, we report the Young's modulus and breaking strength of multilayered InSe, an emerging 2D semiconductor of the layered group III chalcogenide. Few-layer InSe flaks were exfoliated from bulk InSe crystal onto Si/SiO2 substrate with micro-fabricated holes, and indentation tests were carried out using an atomic force microscopy probe. In combination with both continuum analysis and finite element simulation, we measured the Young's modulus of multilayer 2D InSe (>5 L) to be 101.37 ± 17.93 GPa, much higher than its bulk counterpart, while its breaking strength is determined to be 8.68 GPa, approaching the theoretical limit of 10.1 GPa. Density functional theory calculations were also carried out to explain the insensitivity of Young's modulus to the layer count. It is found that 2D InSe is softer than most 2D materials, and exhibits breaking strength higher than that of carbon fiber, yet remaining more compliant, making it ideal for flexible electronics applications. The reliability of our method is also validated by measurement of graphene.
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Affiliation(s)
- Yuhao Li
- State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics & Astronautics, Nanjing 210016, Jiangsu, People's Republic of China. Shenzhen Key Laboratory of Nanobiomechanics, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, Guangdong, People's Republic of China
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95
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Sang DK, Wen B, Gao S, Zeng Y, Meng F, Guo Z, Zhang H. Electronic and Optical Properties of Two-Dimensional Tellurene: From First-Principles Calculations. NANOMATERIALS (BASEL, SWITZERLAND) 2019; 9:E1075. [PMID: 31357462 PMCID: PMC6722590 DOI: 10.3390/nano9081075] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2019] [Revised: 07/19/2019] [Accepted: 07/22/2019] [Indexed: 02/04/2023]
Abstract
Tellurene is a new-emerging two-dimensional anisotropic semiconductor, with fascinating electric and optical properties that differ dramatically from the bulk counterpart. In this work, the layer dependent electronic and optical properties of few-layer Tellurene has been calculated with the density functional theory (DFT). It shows that the band gap of the Tellurene changes from direct to indirect when layer number changes from monolayer (1 L) to few-layers (2 L-6 L) due to structural reconstruction. Tellurene also has an energy gap that can be tuned from 1.0 eV (1 L) to 0.3 eV (6 L). Furthermore, due to the interplay of spin-orbit coupling (SOC) and disappearance of inversion symmetry in odd-numbered layer structures resulting in the anisotropic SOC splitting, the decrease of the band gap with an increasing layer number is not monotonic but rather shows an odd-even quantum confinement effect. The optical results in Tellurene are layer dependent and different in E ⊥ C and E || C directions. The correlations between the structure, the electronic and optical properties of the Tellurene have been identified. Despite the weak nature of interlayer forces in their structure, their electronic and optical properties are highly dependent on the number of layers and highly anisotropic. These results are essential in the realization of its full potential and recommended for experimental exploration.
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Affiliation(s)
- David K Sang
- Shenzhen Engineering Laboratory of Phosphorene and Optoelectronics, Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, Engineering Technology Research Center for 2D Material Information Function Devices and Systems of Guangdong Province, Shenzhen University, Shenzhen 518060, China
| | - Bo Wen
- Shenzhen Engineering Laboratory of Phosphorene and Optoelectronics, Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, Engineering Technology Research Center for 2D Material Information Function Devices and Systems of Guangdong Province, Shenzhen University, Shenzhen 518060, China
| | - Shan Gao
- Shenzhen Engineering Laboratory of Phosphorene and Optoelectronics, Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, Engineering Technology Research Center for 2D Material Information Function Devices and Systems of Guangdong Province, Shenzhen University, Shenzhen 518060, China
| | - Yonghong Zeng
- Shenzhen Engineering Laboratory of Phosphorene and Optoelectronics, Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, Engineering Technology Research Center for 2D Material Information Function Devices and Systems of Guangdong Province, Shenzhen University, Shenzhen 518060, China
| | - Fanxu Meng
- Shenzhen Engineering Laboratory of Phosphorene and Optoelectronics, Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, Engineering Technology Research Center for 2D Material Information Function Devices and Systems of Guangdong Province, Shenzhen University, Shenzhen 518060, China
| | - Zhinan Guo
- Shenzhen Engineering Laboratory of Phosphorene and Optoelectronics, Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, Engineering Technology Research Center for 2D Material Information Function Devices and Systems of Guangdong Province, Shenzhen University, Shenzhen 518060, China.
| | - Han Zhang
- Shenzhen Engineering Laboratory of Phosphorene and Optoelectronics, Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, Engineering Technology Research Center for 2D Material Information Function Devices and Systems of Guangdong Province, Shenzhen University, Shenzhen 518060, China.
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96
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Modulation of Electronic Behaviors of InSe Nanosheet and Nanoribbons: The First‐Principles Study. ADVANCED THEORY AND SIMULATIONS 2019. [DOI: 10.1002/adts.201900099] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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97
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Zhou N, Gan L, Yang R, Wang F, Li L, Chen Y, Li D, Zhai T. Nonlayered Two-Dimensional Defective Semiconductor γ-Ga 2S 3 toward Broadband Photodetection. ACS NANO 2019; 13:6297-6307. [PMID: 31082203 DOI: 10.1021/acsnano.9b00276] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Two-dimensional (2D) materials exhibit high sensitivity to structural defects due to the nature of interface-type materials, and the corresponding structural defects can effectively modulate their inherent properties in turn, giving them a wide application range in high-performance and functional devices. 2D γ-Ga2S3 is a defective semiconductor with outstanding optoelectronic properties. However, its controllable preparation has not been implemented yet, which hinders exploring its potential applications. In this work, we introduce nonlayered γ-Ga2S3 into the 2D materials family, which was successfully synthesized via the space-confined chemical vapor deposition method. Its intriguing defective structure are revealed by high-resolution transmission electron microscopy and temperature-dependent cathodoluminescence spectra, which endow the γ-Ga2S3-based device with a broad photoresponse from the ultraviolet to near-infrared region and excellent photoelectric conversion capability. Simultaneously, the device also exhibits excellent ultraviolet detection ability ( Rλ = 61.3 A W-1, Ion /Ioff = 851, EQE = 2.17× 104 %, D* = 1.52× 1010 Jones @350 nm), and relatively fast response (15 ms). This work provides a feasible way to fabricate ultrathin nonlayered materials and explore the potential applications of a 2D defective semiconductor in high-performance broadband photodetection, which also suggests a promising future of defect creation in optimizing photoelectric properties.
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Affiliation(s)
- Nan Zhou
- State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering , Huazhong University of Science and Technology , Wuhan 430074 , People's Republic of China
- School of Advanced Materials and Nanotechnology , Xidian University , Xi'an 710126 , People's Republic of China
| | - Lin Gan
- State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering , Huazhong University of Science and Technology , Wuhan 430074 , People's Republic of China
| | - Rusen Yang
- School of Advanced Materials and Nanotechnology , Xidian University , Xi'an 710126 , People's Republic of China
| | - Fakun Wang
- State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering , Huazhong University of Science and Technology , Wuhan 430074 , People's Republic of China
| | - Liang Li
- State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering , Huazhong University of Science and Technology , Wuhan 430074 , People's Republic of China
| | - Yicong Chen
- State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering , Huazhong University of Science and Technology , Wuhan 430074 , People's Republic of China
| | - Dehui Li
- School of Optical and Electronic Information, Wuhan National Laboratory for Optoelectronics , Huazhong University of Science and Technology , Wuhan 430074 , People's Republic of China
| | - Tianyou Zhai
- State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering , Huazhong University of Science and Technology , Wuhan 430074 , People's Republic of China
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98
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Maeso D, Pakdel S, Santos H, Agraït N, Palacios JJ, Prada E, Rubio-Bollinger G. Strong modulation of optical properties in rippled 2D GaSe via strain engineering. NANOTECHNOLOGY 2019; 30:24LT01. [PMID: 30822757 DOI: 10.1088/1361-6528/ab0bc1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Few-layer GaSe is one of the latest additions to the family of two-dimensional semiconducting crystals whose properties under strain are still relatively unexplored. Here, we study rippled nanosheets that exhibit a periodic compressive and tensile strain of up to 5%. The strain profile modifies the local optoelectronic properties of the alternating compressive and tensile regions, which translates into a remarkable shift of the optical absorption band-edge of up to 1.2 eV between crests and valleys. Our experimental observations are supported by theoretical results from density functional theory calculations performed for monolayers and multilayers (up to seven layers) under tensile and compressive strain. This large band gap tunability can be explained through a combined analysis of the elastic response of Ga atoms to strain and the symmetry of the wave functions.
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Affiliation(s)
- David Maeso
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, E-28049, Madrid, Spain
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99
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Hopkinson DG, Zólyomi V, Rooney AP, Clark N, Terry DJ, Hamer M, Lewis DJ, Allen CS, Kirkland AI, Andreev Y, Kudrynskyi Z, Kovalyuk Z, Patanè A, Fal'ko VI, Gorbachev R, Haigh SJ. Formation and Healing of Defects in Atomically Thin GaSe and InSe. ACS NANO 2019; 13:5112-5123. [PMID: 30946569 DOI: 10.1021/acsnano.8b08253] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Two dimensional III-VI metal monochalcogenide materials, such as GaSe and InSe, are attracting considerable attention due to their promising electronic and optoelectronic properties. Here, an investigation of point and extended atomic defects formed in mono-, bi-, and few-layer GaSe and InSe crystals is presented. Using state-of-the-art scanning transmission electron microscopy, it is observed that these materials can form both metal and selenium vacancies under the action of the electron beam. Selenium vacancies are observed to be healable: recovering the perfect lattice structure in the presence of selenium or enabling incorporation of dopant atoms in the presence of impurities. Under prolonged imaging, multiple point defects are observed to coalesce to form extended defect structures, with GaSe generally developing trigonal defects and InSe primarily forming line defects. These insights into atomic behavior could be harnessed to synthesize and tune the properties of 2D post-transition-metal monochalcogenide materials for optoelectronic applications.
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Affiliation(s)
- David G Hopkinson
- National Graphene Institute , University of Manchester , Booth Street East , Manchester M13 9PL , United Kingdom
- School of Materials , University of Manchester , Oxford Road , Manchester M13 9PL , United Kingdom
| | - Viktor Zólyomi
- National Graphene Institute , University of Manchester , Booth Street East , Manchester M13 9PL , United Kingdom
- School of Physics and Astronomy , University of Manchester , Oxford Road , Manchester M13 9PL , United Kingdom
| | - Aidan P Rooney
- School of Materials , University of Manchester , Oxford Road , Manchester M13 9PL , United Kingdom
| | - Nick Clark
- National Graphene Institute , University of Manchester , Booth Street East , Manchester M13 9PL , United Kingdom
- School of Materials , University of Manchester , Oxford Road , Manchester M13 9PL , United Kingdom
| | - Daniel J Terry
- National Graphene Institute , University of Manchester , Booth Street East , Manchester M13 9PL , United Kingdom
- School of Physics and Astronomy , University of Manchester , Oxford Road , Manchester M13 9PL , United Kingdom
| | - Matthew Hamer
- National Graphene Institute , University of Manchester , Booth Street East , Manchester M13 9PL , United Kingdom
- School of Physics and Astronomy , University of Manchester , Oxford Road , Manchester M13 9PL , United Kingdom
| | - David J Lewis
- School of Materials , University of Manchester , Oxford Road , Manchester M13 9PL , United Kingdom
| | - Christopher S Allen
- Electron Physical Sciences Imaging Centre , Diamond Light Source Ltd. , Didcot , Oxfordshire OX11 0DE , United Kingdom
- Department of Materials , University of Oxford , Parks Road , Oxford OX1 3PH , United Kingdom
| | - Angus I Kirkland
- Electron Physical Sciences Imaging Centre , Diamond Light Source Ltd. , Didcot , Oxfordshire OX11 0DE , United Kingdom
- Department of Materials , University of Oxford , Parks Road , Oxford OX1 3PH , United Kingdom
| | - Yuri Andreev
- National Tomsk State Research University , 634050 Tomsk , Russian Federation
| | - Zakhar Kudrynskyi
- School of Physics and Astronomy , University of Nottingham , Nottingham NG7 2RD , United Kingdom
| | - Zakhar Kovalyuk
- Institute for Problems of Materials Science , National Academy of Sciences of Ukraine , Chernivtsi Branch, 58001 Chernivtsi , Ukraine
| | - Amalia Patanè
- School of Physics and Astronomy , University of Nottingham , Nottingham NG7 2RD , United Kingdom
| | - Vladimir I Fal'ko
- National Graphene Institute , University of Manchester , Booth Street East , Manchester M13 9PL , United Kingdom
- School of Physics and Astronomy , University of Manchester , Oxford Road , Manchester M13 9PL , United Kingdom
- Henry Royce Institute for Advanced Materials , Manchester M13 9PL , United Kingdom
| | - Roman Gorbachev
- National Graphene Institute , University of Manchester , Booth Street East , Manchester M13 9PL , United Kingdom
- School of Physics and Astronomy , University of Manchester , Oxford Road , Manchester M13 9PL , United Kingdom
- Henry Royce Institute for Advanced Materials , Manchester M13 9PL , United Kingdom
| | - Sarah J Haigh
- National Graphene Institute , University of Manchester , Booth Street East , Manchester M13 9PL , United Kingdom
- School of Materials , University of Manchester , Oxford Road , Manchester M13 9PL , United Kingdom
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100
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Feng W, Qin F, Yu M, Gao F, Dai M, Hu Y, Wang L, Hou J, Li B, Hu P. Synthesis of Superlattice InSe Nanosheets with Enhanced Electronic and Optoelectronic Performance. ACS APPLIED MATERIALS & INTERFACES 2019; 11:18511-18516. [PMID: 31059223 DOI: 10.1021/acsami.9b01747] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Multilayer InSe has emerged as a promising candidate for applications in novel electronic and optoelectronic devices due to its direct bandgap, high electron mobility, and excellent photoresponse with a broad response range. Here, we report synthesis of superlattice InSe nanosheets by simple thermal annealing for the first time. The mobility is increased to 299.1 cm2 V-1 s-1 for superlattice InSe FETs and is 4 times higher than 63.5 cm2 V-1 s-1 of pristine InSe device. The superlattice InSe photodetector shows an ultrahigh responsivity of 1.7 × 104 A/W (700 nm), which is 8.5 times greater than the pristine photodetector. Superlattice InSe photodetectors hold a good photoresponse stability and rapid response time of 20 ms. The electronic and photoresponse performance improvement of superlattice InSe is attributed to higher carrier sheet density and lower contact resistance for more effective electron injection and more photogenerated carrier injection, respectively. Those results suggest that superlattice is an effective method to further improve electronic and optoelectronic properties of two-dimensional InSe devices.
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Affiliation(s)
| | | | | | - Feng Gao
- Key Lab of Microsystem and Microstructure of Ministry of Education , Harbin Institute of Technology , Harbin , 150080 , China
| | - Mingjin Dai
- Key Lab of Microsystem and Microstructure of Ministry of Education , Harbin Institute of Technology , Harbin , 150080 , China
| | - Yunxia Hu
- Key Lab of Microsystem and Microstructure of Ministry of Education , Harbin Institute of Technology , Harbin , 150080 , China
| | - Lifeng Wang
- Institute for Frontier Materials , Deakin University , 75 Pigdons Road, Waurn Ponds , Geelong , Victoria 3216 , Australia
| | | | | | - PingAn Hu
- Key Lab of Microsystem and Microstructure of Ministry of Education , Harbin Institute of Technology , Harbin , 150080 , China
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