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Determining the Optimized Interlayer Separation Distance in Vertical Stacked 2D WS2:hBN:MoS2 Heterostructures for Exciton Energy Transfer 
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下载免费PDF全文 Wenshuo Xu Daichi Kozawa Yu Liu Yuewen Sheng Ke Wei Volodymyr B. Koman Shanshan Wang Xiaochen Wang Tian Jiang Michael S. Strano Jamie H. Warner 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(13)
The 2D semiconductor monolayer transition metal dichalcogenides, WS2 and MoS2, are grown by chemical vapor deposition (CVD) and assembled by sequential transfer into vertical layered heterostructures (VLHs). Insulating hBN, also produced by CVD, is utilized to control the separation between WS2 and MoS2 by adjusting the layer number, leading to fine‐scale tuning of the interlayer interactions within the VLHs. The interlayer interactions are studied by photoluminescence (PL) spectroscopy and are demonstrated to be highly sensitive to the input excitation power. For thin hBN separators (one to two layers), the total PL emission switches from quenching to enhancement by increasing the laser power. Femtosecond broadband transient absorption measurements demonstrate that the increase in PL quantum yield results from Förster energy transfer from MoS2 to WS2. The PL signal is further enhanced at cryogenic temperatures due to the suppressed nonradiative decay channels. It is shown that (4 ± 1) layers of hBN are optimum for obtaining PL enhancement in the VLHs. Increasing thickness beyond this causes the enhancement factor to diminish, with the WS2 and MoS2 then behaving as isolated noninteracting monolayers. These results indicate how controlling the exciton generation rate influences energy transfer and plays an important role in the properties of VLHs. 相似文献
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2D Materials: Rotation‐Misfit‐Free Heteroepitaxial Stacking and Stitching Growth of Hexagonal Transition‐Metal Dichalcogenide Monolayers by Nucleation Kinetics Controls (Adv. Mater. 25/2015) 下载免费PDF全文
下载免费PDF全文 Hoseok Heo Ji Ho Sung Gangtae Jin Ji‐Hoon Ahn Kyungwook Kim Myoung‐Jae Lee Soonyoung Cha Hyunyong Choi Moon‐Ho Jo 《Advanced materials (Deerfield Beach, Fla.)》2015,27(25):3839-3839
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Daniele Chiappe Inge Asselberghs Surajit Sutar Serena Iacovo Valeri Afanas'ev Andre Stesmans Yashwanth Balaji Lisanne Peters Markus Heyne Manuel Mannarino Wilfried Vandervorst Safak Sayan Cedric Huyghebaert Matty Caymax Marc Heyns Stefan De Gendt Iuliana Radu Aaron Thean 《Advanced Materials Interfaces》2016,3(4)
Large area MoS2 films with tunable physical‐chemical properties are grown on dielectric substrates by annealing of ultrathin Mo layers in the presence of a sulfur‐containing gaseous precursor. Different growth conditions are found to have a significant impact on material properties, including chemical composition, roughness, and grain sizes, thus shedding light on critical parameters that govern sulfurization processes for the synthesis of large area 2D transition metal dichalcogenides. Optimized growth conditions in combination with the use of single crystal sapphire substrates with atomically flat interface result in the formation of oriented MoS2 films with improved quality and electrical performance. On the basis of this versatile synthesis technique, an original double‐step process is presented for the synthesis of WS2/MoS2 vertical heterostructures. Good uniformity of layers over large area has enabled first isolation of defects by electron spin resonance spectroscopy with densities correlated with mobility degradation and the first experimental characterization of the band alignment at the interfaces of MoS2, WS2, and their vertical stacks with the underlying SiO2 insulator. 相似文献
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Shuai Jia Zehua Jin Jing Zhang Jiangtan Yuan Weibing Chen Wei Feng Pingan Hu Pulickel M. Ajayan Jun Lou 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(34)
2D transition metal dichalcogenides (TMDs) have exhibited strong application potentials in new emerging electronics because of their atomic thin structure and excellent flexibility, which is out of field of tradition silicon technology. Similar to 3D p–n junctions, 2D p–n heterojunctions by laterally connecting TMDs with different majority charge carriers (electrons and holes), provide ideal platform for current rectifiers, light‐emitting diodes, diode lasers and photovoltaic devices. Here, growth and electrical studies of atomic thin high‐quality p–n heterojunctions between molybdenum diselenide (MoSe2) and tungsten diselenide (WSe2) by one‐step chemical vapor deposition method are reported. These p–n heterojunctions exhibit high built‐in potential (≈0.7 eV), resulting in large current rectification ratio without any gate control for diodes, and fast response time (≈6 ms) for self‐powered photodetectors. The simple one‐step growth and electrical studies of monolayer lateral heterojunctions open up the possibility to use TMD heterojunctions for functional devices. 相似文献
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Meng‐Lin Tsai Ming‐Yang Li José Ramón Durán Retamal Kai‐Tak Lam Yung‐Chang Lin Kazu Suenaga Lih‐Juann Chen Gengchiau Liang Lain‐Jong Li Jr‐Hau He 《Advanced materials (Deerfield Beach, Fla.)》2017,29(32)
The recent development of 2D monolayer lateral semiconductor has created new paradigm to develop p‐n heterojunctions. Albeit, the growth methods of these heterostructures typically result in alloy structures at the interface, limiting the development for high‐efficiency photovoltaic (PV) devices. Here, the PV properties of sequentially grown alloy‐free 2D monolayer WSe2‐MoS2 lateral p‐n heterojunction are explores. The PV devices show an extraordinary power conversion efficiency of 2.56% under AM 1.5G illumination. The large surface active area enables the full exposure of the depletion region, leading to excellent omnidirectional light harvesting characteristic with only 5% reduction of efficiency at incident angles up to 75°. Modeling studies demonstrate the PV devices comply with typical principles, increasing the feasibility for further development. Furthermore, the appropriate electrode‐spacing design can lead to environment‐independent PV properties. These robust PV properties deriving from the atomically sharp lateral p‐n interface can help develop the next‐generation photovoltaics. 相似文献
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2D Materials: Single Atomically Sharp Lateral Monolayer p‐n Heterojunction Solar Cells with Extraordinarily High Power Conversion Efficiency (Adv. Mater. 32/2017) 下载免费PDF全文
下载免费PDF全文 Meng‐Lin Tsai Ming‐Yang Li José Ramón Durán Retamal Kai‐Tak Lam Yung‐Chang Lin Kazu Suenaga Lih‐Juann Chen Gengchiau Liang Lain‐Jong Li Jr‐Hau He 《Advanced materials (Deerfield Beach, Fla.)》2017,29(32)
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Yu Zhang Yuyu Yao Marshet Getaye Sendeku Lei Yin Xueying Zhan Feng Wang Zhenxing Wang Jun He 《Advanced materials (Deerfield Beach, Fla.)》2019,31(41)
In recent years, 2D layered materials have received considerable research interest on account of their substantial material systems and unique physicochemical properties. Among them, 2D layered transition metal dichalcogenides (TMDs), a star family member, have already been explored over the last few years and have exhibited excellent performance in electronics, catalysis, and other related fields. However, to fulfill the requirement for practical application, the batch production of 2D TMDs is essential. Recently, the chemical vapor deposition (CVD) technique was considered as an elegant alternative for successfully growing 2D TMDs and their heterostructures. The latest research advances in the controllable synthesis of 2D TMDs and related heterostructures/superlattices via the CVD approach are illustrated here. The controlled growth behavior, preparation strategies, and breakthroughs on the synthesis of new 2D TMDs and their heterostructures, as well as their unique physical phenomena, are also discussed. Recent progress on the application of CVD‐grown 2D materials is revealed with particular attention to electronics/optoelectronic devices and catalysts. Finally, the challenges and future prospects are considered regarding the current development of 2D TMDs and related heterostructures. 相似文献
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Eli Janzen Hannah Schutte Juliette Plo Adrien Rousseau Thierry Michel Wilfried Desrat Pierre Valvin Vincent Jacques Guillaume Cassabois Bernard Gil James H. Edgar 《Advanced materials (Deerfield Beach, Fla.)》2024,36(2):2306033
The unique physical, mechanical, chemical, optical, and electronic properties of hexagonal boron nitride (hBN) make it a promising 2D material for electronic, optoelectronic, nanophotonic, and quantum devices. Here, the changes in hBN's properties induced by isotopic purification in both boron and nitrogen are reported. Previous studies on isotopically pure hBN have focused on purifying the boron isotope concentration in hBN from its natural concentration (≈20 at% 10B, 80 at% 11B) while using naturally abundant nitrogen (99.6 at% 14N, 0.4 at% 15N), that is, almost pure 14N. In this study, the class of isotopically purified hBN crystals to 15N is extended. Crystals in the four configurations, namely h10B14N, h11B14N, h10B15N, and h11B15N, are grown by the metal flux method using boron and nitrogen single isotope (> 99%) enriched sources, with nickel plus chromium as the solvent. In-depth Raman and photoluminescence spectroscopies demonstrate the high quality of the monoisotopic hBN crystals with vibrational and optical properties of the 15N-purified crystals at the state-of-the-art of currently available 14N-purified hBN. The growth of high-quality h10B14N, h11B14N, h10B15N, and h11B15N opens exciting perspectives for thermal conductivity control in heat management, as well as for advanced functionalities in quantum technologies. 相似文献
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Poya Yasaei Akshay A. Murthy Yaobin Xu Roberto dos Reis Gajendra S. Shekhawat Vinayak P. Dravid 《Advanced materials (Deerfield Beach, Fla.)》2019,31(24)
Lateral heterogeneities in atomically thin 2D materials such as in‐plane heterojunctions and grain boundaries (GBs) provide an extrinsic knob for manipulating the properties of nano‐ and optoelectronic devices and harvesting novel functionalities. However, these heterogeneities have the potential to adversely affect the performance and reliability of the 2D devices through the formation of nanoscopic hot‐spots. In this report, scanning thermal microscopy (SThM) is utilized to map the spatial distribution of the temperature rise within monolayer transition metal dichalcogenide (TMD) devices upon dissipating a high electrical power through a lateral interface. The results directly demonstrate that lateral heterojunctions between MoS2 and WS2 do not largely impact the distribution of heat dissipation, while GBs of MoS2 appreciably localize heating in the device. High‐resolution scanning transmission electron microscopy reveals that the atomic structure is nearly flawless around heterojunctions but can be quite defective near GBs. The results suggest that the interfacial atomic structure plays a crucial role in enabling uniform charge transport without inducing localized heating. Establishing such structure–property‐processing correlation provides a better understanding of lateral heterogeneities in 2D TMD systems which is crucial in the design of future all‐2D electronic circuitry with enhanced functionalities, lifetime, and performance. 相似文献
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Alei Li Qianxue Chen Peipei Wang Yuan Gan Tailei Qi Peng Wang Fangdong Tang Judy Z. Wu Rui Chen Liyuan Zhang Youpin Gong 《Advanced materials (Deerfield Beach, Fla.)》2019,31(6)
2D atomic sheets of transition metal dichalcogenides (TMDs) have a tremendous potential for next‐generation optoelectronics since they can be stacked layer‐by‐layer to form van der Waals (vdW) heterostructures. This allows not only bypassing difficulties in heteroepitaxy of lattice‐mismatched semiconductors of desired functionalities but also providing a scheme to design new optoelectronics that can surpass the fundamental limitations on their conventional semiconductor counterparts. Herein, a novel 2D h‐BN/p‐MoTe2/graphene/n‐SnS2/h‐BN p–g–n junction, fabricated by a layer‐by‐layer dry transfer, demonstrates high‐sensitivity, broadband photodetection at room temperature. The combination of the MoTe2 and SnS2 of complementary bandgaps, and the graphene interlayer provides a unique vdW heterostructure with a vertical built‐in electric field for high‐efficiency broadband light absorption, exciton dissociation, and carrier transfer. The graphene interlayer plays a critical role in enhancing sensitivity and broadening the spectral range. An optimized device containing 5?7‐layer graphene has been achieved and shows an extraordinary responsivity exceeding 2600 A W?1 with fast photoresponse and specific detectivity up to ≈1013 Jones in the ultraviolet–visible–near‐infrared spectrum. This result suggests that the vdW p–g–n junctions containing multiple photoactive TMDs can provide a viable approach toward future ultrahigh‐sensitivity and broadband photonic detectors. 相似文献
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Monolayer Multijunctions: Synthesis of In‐Plane Artificial Lattices of Monolayer Multijunctions (Adv. Mater. 7/2018) 下载免费PDF全文
下载免费PDF全文 Kuan‐Chang Chiu Kuan‐Hua Huang Chun‐An Chen Ying‐Yu Lai Xin‐Quan Zhang Erh‐Chen Lin Meng‐Hsi Chuang Jenn‐Ming Wu Yi‐Hsien Lee 《Advanced materials (Deerfield Beach, Fla.)》2018,30(7)
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Kuan‐Chang Chiu Kuan‐Hua Huang Chun‐An Chen Ying‐Yu Lai Xin‐Quan Zhang Erh‐Chen Lin Meng‐Hsi Chuang Jenn‐Ming Wu Yi‐Hsien Lee 《Advanced materials (Deerfield Beach, Fla.)》2018,30(7)
Recently, monolayers of van der Waals materials, including transition metal dichalcogenides (TMDs), are considered ideal building blocks for constructing 2D artificial lattices and heterostructures. Heterostructures with multijunctions of more than two monolayer TMDs are intriguing for exploring new physics and materials properties. Obtaining in‐plane heterojunctions of monolayer TMDs with atomically sharp interfaces is very significant for fundamental research and applications. Currently, multistep synthesis for more than two monolayer TMDs remains a challenge because decomposition or compositional alloying is thermodynamically favored at the high growth temperature. Here, a multistep chemical vapor deposition (CVD) synthesis of the in‐plane multijunctions of monolayer TMDs is presented. A low growth temperature synthesis is developed to avoid compositional fluctuations of as‐grown TMDs, defects formations, and interfacial alloying for high heterointerface quality and thermal stability of monolayer TMDs. With optimized parameters, atomically sharp interfaces are successfully achieved in the synthesis of in‐plane artificial lattices of the WS2/WSe2/MoS2 at reduced growth temperatures. Growth behaviors as well as the heterointerface quality are carefully studied in varying growth parameters. Highly oriented strain patterns are found in the second harmonic generation imaging of the TMD multijunctions, suggesting that the in‐plane heteroepitaxial growth may induce distortion for unique material symmetry. 相似文献
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Gia Quyet Ngo Antony George Robin Tristan Klaus Schock Alessandro Tuniz Emad Najafidehaghani Ziyang Gan Nils C. Geib Tobias Bucher Heiko Knopf Sina Saravi Christof Neumann Tilman Lühder Erik P. Schartner Stephen C. Warren-Smith Heike Ebendorff-Heidepriem Thomas Pertsch Markus A. Schmidt Andrey Turchanin Falk Eilenberger 《Advanced materials (Deerfield Beach, Fla.)》2020,32(47):2003826
Atomically thin transition metal dichalcogenides are highly promising for integrated optoelectronic and photonic systems due to their exciton-driven linear and nonlinear interactions with light. Integrating them into optical fibers yields novel opportunities in optical communication, remote sensing, and all-fiber optoelectronics. However, the scalable and reproducible deposition of high-quality monolayers on optical fibers is a challenge. Here, the chemical vapor deposition of monolayer MoS2 and WS2 crystals on the core of microstructured exposed-core optical fibers and their interaction with the fibers’ guided modes are reported. Two distinct application possibilities of 2D-functionalized waveguides to exemplify their potential are demonstrated. First, the excitonic 2D material photoluminescence is simultaneously excited and collected with the fiber modes, opening a novel route to remote sensing. Then it is shown that third-harmonic generation is modified by the highly localized nonlinear polarization of the monolayers, yielding a new avenue to tailor nonlinear optical processes in fibers. It is anticipated that the results may lead to significant advances in optical-fiber-based technologies. 相似文献
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Mengmeng Fan Jingjie Wu Jiangtan Yuan Liangzi Deng Ning Zhong Liang He Jiewu Cui Zixing Wang Sushant Kumar Behera Chenhao Zhang Jiawei Lai BenMaan I. Jawdat Robert Vajtai Pritam Deb Yang Huang Jieshu Qian Jiazhi Yang James M. Tour Jun Lou Ching‐Wu Chu Dongping Sun Pulickel M. Ajayan 《Advanced materials (Deerfield Beach, Fla.)》2019,31(12)
Carbon doping can induce unique and interesting physical properties in hexagonal boron nitride (h‐BN). Typically, isolated carbon atoms are doped into h‐BN. Herein, however, the insertion of nanometer‐scale graphene quantum dots (GQDs) is demonstrated as whole units into h‐BN sheets to form h‐CBN. The h‐CBN is prepared by using GQDs as seed nucleations for the epitaxial growth of h‐BN along the edges of GQDs without the assistance of metal catalysts. The resulting h‐CBN sheets possess a uniform distrubution of GQDs in plane and a high porosity macroscopically. The h‐CBN tends to form in small triangular sheets which suggests an enhanced crystallinity compared to the h‐BN synthesized under the same conditions without GQDs. An enhanced ferromagnetism in the h‐CBN emerges due to the spin polarization and charge asymmetry resulting from the high density of C? N and C? B bonds at the boundary between the GQDs and the h‐BN domains. The saturation magnetic moment of h‐CBN reaches 0.033 emu g?1 at 300 K, which is three times that of as‐prepared single carbon‐doped h‐BN. 相似文献