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Krause R, Aeschlimann S, Chávez-Cervantes M, Perea-Causin R, Brem S, Malic E, Forti S, Fabbri F, Coletti C, Gierz I. Microscopic Understanding of Ultrafast Charge Transfer in van der Waals Heterostructures. PHYSICAL REVIEW LETTERS 2021; 127:276401. [PMID: 35061410 DOI: 10.1103/physrevlett.127.276401] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 09/29/2021] [Accepted: 11/12/2021] [Indexed: 06/14/2023]
Abstract
Van der Waals heterostructures show many intriguing phenomena including ultrafast charge separation following strong excitonic absorption in the visible spectral range. However, despite the enormous potential for future applications in the field of optoelectronics, the underlying microscopic mechanism remains controversial. Here we use time- and angle-resolved photoemission spectroscopy combined with microscopic many-particle theory to reveal the relevant microscopic charge transfer channels in epitaxial WS_{2}/graphene heterostructures. We find that the timescale for efficient ultrafast charge separation in the material is determined by direct tunneling at those points in the Brillouin zone where WS_{2} and graphene bands cross, while the lifetime of the charge separated transient state is set by defect-assisted tunneling through localized sulphur vacancies. The subtle interplay of intrinsic and defect-related charge transfer channels revealed in the present work can be exploited for the design of highly efficient light harvesting and detecting devices.
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Affiliation(s)
- R Krause
- University of Regensburg, Institute for Experimental and Applied Physics, 93040 Regensburg, Germany
- Max Planck Institute for the Structure and Dynamics of Matter, Center for Free Electron Laser Science, 22761 Hamburg, Germany
| | - S Aeschlimann
- University of Regensburg, Institute for Experimental and Applied Physics, 93040 Regensburg, Germany
- Max Planck Institute for the Structure and Dynamics of Matter, Center for Free Electron Laser Science, 22761 Hamburg, Germany
| | - M Chávez-Cervantes
- Max Planck Institute for the Structure and Dynamics of Matter, Center for Free Electron Laser Science, 22761 Hamburg, Germany
| | - R Perea-Causin
- Chalmers University of Technology, Department of Physics, 41296 Gothenburg, Sweden
| | - S Brem
- Philipps-Universität Marburg, Department of Physics, 35032 Marburg, Germany
| | - E Malic
- Chalmers University of Technology, Department of Physics, 41296 Gothenburg, Sweden
- Philipps-Universität Marburg, Department of Physics, 35032 Marburg, Germany
| | - S Forti
- Center for Nanotechnology Innovation at NEST, Istituto Italiano di Tecnologia, 56127 Pisa, Italy
| | - F Fabbri
- Center for Nanotechnology Innovation at NEST, Istituto Italiano di Tecnologia, 56127 Pisa, Italy
- NEST, Istituto Nanoscienze, CNR and Scuola Normale Superiore, 56127 Pisa, Italy
- Graphene Labs, Istituto Italiano di Tecnologia, 16163 Genova, Italy
| | - C Coletti
- Center for Nanotechnology Innovation at NEST, Istituto Italiano di Tecnologia, 56127 Pisa, Italy
- Graphene Labs, Istituto Italiano di Tecnologia, 16163 Genova, Italy
| | - I Gierz
- University of Regensburg, Institute for Experimental and Applied Physics, 93040 Regensburg, Germany
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2
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Luo D, Tang J, Shen X, Ji F, Yang J, Weathersby S, Kozina ME, Chen Z, Xiao J, Ye Y, Cao T, Zhang G, Wang X, Lindenberg AM. Twist-Angle-Dependent Ultrafast Charge Transfer in MoS 2-Graphene van der Waals Heterostructures. NANO LETTERS 2021; 21:8051-8057. [PMID: 34529439 DOI: 10.1021/acs.nanolett.1c02356] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Vertically stacked transition metal dichalcogenide-graphene heterostructures provide a platform for novel optoelectronic applications with high photoresponse speeds. Photoinduced nonequilibrium carrier and lattice dynamics in such heterostructures underlie these applications but have not been understood. In particular, the dependence of these photoresponses on the twist angle, a key tuning parameter, remains elusive. Here, using ultrafast electron diffraction, we report the simultaneous visualization of charge transfer and electron-phonon coupling in MoS2-graphene heterostructures with different stacking configurations. We find that the charge transfer timescale from MoS2 to graphene varies strongly with twist angle, becoming faster for smaller twist angles, and show that the relaxation timescale is significantly shorter in a heterostructure as compared to a monolayer. These findings illustrate that twist angle constitutes an additional tuning knob for interlayer charge transfer in heterobilayers and deepen our understanding of fundamental photophysical processes in heterostructures, of importance for future applications in optoelectronics and light harvesting.
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Affiliation(s)
- Duan Luo
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Jian Tang
- Beijing National Laboratory for Condensed Matter Physics, Key Laboratory for Nanoscale Physics and Devices, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Xiaozhe Shen
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Fuhao Ji
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Jie Yang
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Stephen Weathersby
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Michael E Kozina
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Zhijiang Chen
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Jun Xiao
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Yusen Ye
- Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, United States
| | - Ting Cao
- Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, United States
| | - Guangyu Zhang
- Beijing National Laboratory for Condensed Matter Physics, Key Laboratory for Nanoscale Physics and Devices, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Xijie Wang
- SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Aaron M Lindenberg
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
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3
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Deng L, Yuan W, He D, Liu S, Du Y, Gong L, Liu H. Transient absorption measurements of interlayer charge transfer in a WS 2/GeS van der Waals heterostructure. Phys Chem Chem Phys 2021; 23:17259-17264. [PMID: 34346436 DOI: 10.1039/d1cp01892b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
We introduce germanium sulfide (GeS) as a new layered material for the fabrication of two-dimensional van der Waals materials and heterostructures. Heterostructures of WS2/GeS were fabricated using mechanical exfoliation and dry transfer techniques. Significant photoluminescence quenching of WS2 in the heterostructures indicates efficient charge transfer. Transient absorption measurements were performed to study the dynamics of charge transfer. The results show that the heterostructure forms a type-II band alignment with the conduction band minimum and valence band maximum located in the WS2 and GeS layers, respectively. The ultrafast hole transfer from WS2 to GeS is confirmed by the faster decay of the lower peak value of the differential reflection signal in the heterostructure sample, in comparison to the WS2 monolayer. These results introduce GeS as a promising semiconductor material for developing new novel heterostructures.
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Affiliation(s)
- Lier Deng
- School of Optoelectronic Engineering, Xi'an Technological University, Xi'an 710032, China.
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4
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Wang X, Long R. Photoinduced Anomalous Electron Transfer Dynamics at a Lateral MoS 2-Graphene Covalent Junction. J Phys Chem Lett 2021; 12:7553-7559. [PMID: 34351765 DOI: 10.1021/acs.jpclett.1c02169] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Photoinduced charge separation significantly affects the optoelectronic performance of the lateral MoS2-graphene junctions. Generally, an adiabatic mechanism governs electron transfer (ET) at a chemically binding interface. Counterintuitively, we demonstrate, using nonadiabatic (NA) molecular dynamics, that an NA mechanism dominates the ET from MoS2 to graphene in the lateral MoS2-graphene covalent junction. The anomalous ET mechanism arising from the built-in electric field formed at the interface that decreases the donor-acceptor interaction by driving electrons and holes moving to opposite directions. Driven by both graphene and MoS2 vibrations, the photoexcited electrons on MoS2 rapidly transfer into graphene by the NA mechanism within 200 fs, which is faster than electron-phonon energy relaxation and ensures that "hot" electrons can be successfully extracted before they cool and lose energy to heat. The study establishes a mechanistic understanding of the complex charge-phonon dynamics in the lateral MoS2-graphene junctions that are key to optoelectronic and photovoltaic applications.
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Affiliation(s)
- Xiaoli Wang
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing, 100875, P. R. China
| | - Run Long
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing, 100875, P. R. China
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5
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Zhou H, Chen Y, Zhu H. Deciphering asymmetric charge transfer at transition metal dichalcogenide-graphene interface by helicity-resolved ultrafast spectroscopy. SCIENCE ADVANCES 2021; 7:7/34/eabg2999. [PMID: 34417175 PMCID: PMC8378813 DOI: 10.1126/sciadv.abg2999] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 07/01/2021] [Indexed: 05/27/2023]
Abstract
Transition metal dichalcogenide (TMD)/graphene (Gr) heterostructures constitute a key component for two-dimensional devices. The operation of TMD/Gr devices relies on interfacial charge/energy transfer processes, which remains unclear and challenging to unravel. Fortunately, the coupled spin and valley index in TMDs adds a new degree of freedom to the charges and, thus, another dimension to spectroscopy. Here, by helicity-resolved ultrafast spectroscopy, we find that photoexcitation in TMDs transfers to graphene by asynchronous charge transfer, with one type of charge transferring in the order of femtoseconds and the other in picoseconds. The rate correlates well with energy offset between TMD and graphene, regardless of compositions and charge species. Spin-polarized hole injection or long-lived polarized hole can be achieved with deliberately designed heterostructures. This study shows helicity-resolved ultrafast spectroscopy as a powerful and facile approach to reveal the fundamental and complex charge/spin dynamics in TMD-based heterostructures, paving the way toward valleytronic and optoelectronic applications.
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Affiliation(s)
- Hongzhi Zhou
- State Key Laboratory of Modern Optical Instrumentation, Key Laboratory of Excited-State Materials of Zhejiang Province, Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Yuzhong Chen
- State Key Laboratory of Modern Optical Instrumentation, Key Laboratory of Excited-State Materials of Zhejiang Province, Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Haiming Zhu
- State Key Laboratory of Modern Optical Instrumentation, Key Laboratory of Excited-State Materials of Zhejiang Province, Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang 310027, China.
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6
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Liu Y, Zhang J, Meng S, Yam C, Frauenheim T. Electric Field Tunable Ultrafast Interlayer Charge Transfer in Graphene/WS 2 Heterostructure. NANO LETTERS 2021; 21:4403-4409. [PMID: 34000186 DOI: 10.1021/acs.nanolett.1c01083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Van der Waals heterostructures composed of two-dimensional materials offer an unprecedented control over their properties and have attracted tremendous research interest in various optoelectronic applications. Here, we study the photoinduced charge transfer in graphene/WS2 heterostructure by time-dependent density functional theory molecular dynamics. Our results show that holes transfer from graphene to WS2 two times faster than electrons, and the occurrence of interlayer charge transfer is found correlated with vibrational modes of graphene and WS2. It is further demonstrated that the carrier dynamics can be efficiently modulated by external electric fields. Detailed analysis confirms that the carrier transfer rate at heterointerface is governed by the coupling between donor and acceptor states, which is the result of the competition between interlayer and intralayer relaxation processes. Our study provides insights into the understanding of ultrafast interlayer charge transfer processes in heterostructures and broadens their future applications in photovoltaic devices.
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Affiliation(s)
- Yuxiang Liu
- Bremen Center for Computational Materials Science, University of Bremen, Am Fallturm 1, 28359 Bremen, Germany
| | - Jin Zhang
- Center for Free Electron Laser Science, Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany
| | - Sheng Meng
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, 100190 Beijing, China
| | - ChiYung Yam
- Beijing Computational Science Research Center, Haidian District, 100193 Beijing, China
- Shenzhen JL Computational Science and Applied Research Institute, 518109 Shenzhen, China
| | - Thomas Frauenheim
- Bremen Center for Computational Materials Science, University of Bremen, Am Fallturm 1, 28359 Bremen, Germany
- Beijing Computational Science Research Center, Haidian District, 100193 Beijing, China
- Shenzhen JL Computational Science and Applied Research Institute, 518109 Shenzhen, China
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7
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Li Y, Zhang L, Chang J, Cui Q, Zhao H. Time-Resolved Observation of Hole Tunneling in van der Waals Multilayer Heterostructures. ACS APPLIED MATERIALS & INTERFACES 2021; 13:12425-12431. [PMID: 33666430 DOI: 10.1021/acsami.1c02913] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We reported a time-resolved study of quantum-mechanical tunneling of holes between two MoSe2 monolayers that are separated by a monolayer WS2 energy barrier. Four-layer heterostructures of MoSe2/WS2/MoSe2/graphene, as well as control samples, were fabricated by mechanical exfoliation and dry transfer techniques. To time-resolve the hole tunneling process, an ultrashort laser pulse was used to excite electrons and holes in both MoSe2 layers. By utilization of the graphene layer to eliminate carriers in the third MoSe2 layer, the first MoSe2 layer is selectively populated with the holes, which then tunnel to the third MoSe2 layer. By monitoring decay of the hole population with an ultrashort probe pulse, we measure a hole tunneling time of about 20 ps, which is found to slightly increase with the injected carrier density. Besides the fundamental interests of real-time observation of the quantum-mechanical tunneling effect across a nanometer barrier, these results provide quantitative understanding on tunneling mechanisms of charge transfer in van der Waals heterostructures, which is useful for designing sophisticated van der Waals multilayer heterostructures.
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Affiliation(s)
- Yuanyuan Li
- Jiangsu Key Laboratory of Meteorological Observation and Information Processing, Nanjing University of Information Science & Technology, Nanjing 210044, China
- Department of Physics and Astronomy, The University of Kansas, Lawrence, Kansas 66045, United States
| | - Lu Zhang
- Jiangsu Key Laboratory of Meteorological Observation and Information Processing, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Jianhua Chang
- Jiangsu Key Laboratory of Meteorological Observation and Information Processing, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Qiannan Cui
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Hui Zhao
- Department of Physics and Astronomy, The University of Kansas, Lawrence, Kansas 66045, United States
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8
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Aeschlimann S, Rossi A, Chávez-Cervantes M, Krause R, Arnoldi B, Stadtmüller B, Aeschlimann M, Forti S, Fabbri F, Coletti C, Gierz I. Direct evidence for efficient ultrafast charge separation in epitaxial WS 2/graphene heterostructures. SCIENCE ADVANCES 2020; 6:eaay0761. [PMID: 32426488 PMCID: PMC7220367 DOI: 10.1126/sciadv.aay0761] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 03/02/2020] [Indexed: 05/27/2023]
Abstract
We use time- and angle-resolved photoemission spectroscopy (tr-ARPES) to investigate ultrafast charge transfer in an epitaxial heterostructure made of monolayer WS2 and graphene. This heterostructure combines the benefits of a direct-gap semiconductor with strong spin-orbit coupling and strong light-matter interaction with those of a semimetal hosting massless carriers with extremely high mobility and long spin lifetimes. We find that, after photoexcitation at resonance to the A-exciton in WS2, the photoexcited holes rapidly transfer into the graphene layer while the photoexcited electrons remain in the WS2 layer. The resulting charge-separated transient state is found to have a lifetime of ∼1 ps. We attribute our findings to differences in scattering phase space caused by the relative alignment of WS2 and graphene bands as revealed by high-resolution ARPES. In combination with spin-selective optical excitation, the investigated WS2/graphene heterostructure might provide a platform for efficient optical spin injection into graphene.
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Affiliation(s)
- Sven Aeschlimann
- Max Planck Institute for the Structure and Dynamics of Matter, Center for Free Electron Laser Science, Luruper Chaussee 149, 22761 Hamburg, Germany
- University of Regensburg, Institute for Experimental and Applied Physics, Universitätsstr. 31, 93053 Regensburg, Germany
| | - Antonio Rossi
- Center for Nanotechnology Innovation at NEST, Istituto Italiano di Tecnologia, Piazza S. Silvestro, 12, 56124 Pisa, Italy
- NEST, Istituto Nanoscienze, CNR and Scuola Normale Superiore, Piazza S. Silvestro, 12, 56124 Pisa, Italy
| | - Mariana Chávez-Cervantes
- Max Planck Institute for the Structure and Dynamics of Matter, Center for Free Electron Laser Science, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Razvan Krause
- Max Planck Institute for the Structure and Dynamics of Matter, Center for Free Electron Laser Science, Luruper Chaussee 149, 22761 Hamburg, Germany
- University of Regensburg, Institute for Experimental and Applied Physics, Universitätsstr. 31, 93053 Regensburg, Germany
| | - Benito Arnoldi
- University of Kaiserslautern, Department of Physics and Research Center OPTIMAS, Erwin Schrödinger Str. 46, 67663 Kaiserslautern, Germany
| | - Benjamin Stadtmüller
- University of Kaiserslautern, Department of Physics and Research Center OPTIMAS, Erwin Schrödinger Str. 46, 67663 Kaiserslautern, Germany
| | - Martin Aeschlimann
- University of Kaiserslautern, Department of Physics and Research Center OPTIMAS, Erwin Schrödinger Str. 46, 67663 Kaiserslautern, Germany
| | - Stiven Forti
- Center for Nanotechnology Innovation at NEST, Istituto Italiano di Tecnologia, Piazza S. Silvestro, 12, 56124 Pisa, Italy
| | - Filippo Fabbri
- Center for Nanotechnology Innovation at NEST, Istituto Italiano di Tecnologia, Piazza S. Silvestro, 12, 56124 Pisa, Italy
- NEST, Istituto Nanoscienze, CNR and Scuola Normale Superiore, Piazza S. Silvestro, 12, 56124 Pisa, Italy
- Graphene Labs, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
| | - Camilla Coletti
- Center for Nanotechnology Innovation at NEST, Istituto Italiano di Tecnologia, Piazza S. Silvestro, 12, 56124 Pisa, Italy
- Graphene Labs, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
| | - Isabella Gierz
- Max Planck Institute for the Structure and Dynamics of Matter, Center for Free Electron Laser Science, Luruper Chaussee 149, 22761 Hamburg, Germany
- University of Regensburg, Institute for Experimental and Applied Physics, Universitätsstr. 31, 93053 Regensburg, Germany
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9
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Hao H, Xu Z, Jiang T, Wei K, Li H, Zheng X, Yin K, You J, Shen C, Cheng XA. Visualized charge transfer processes in monolayer composition-graded WS 2xSe 2(1-x) lateral heterojunctions via ultrafast microscopy mapping. OPTICS EXPRESS 2018; 26:15867-15886. [PMID: 30114841 DOI: 10.1364/oe.26.015867] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 05/21/2018] [Indexed: 06/08/2023]
Abstract
Two-dimensional transitional metal dichalcogenides (TMDCs) based lateral heterojunctions have emerged as appealing and intriguing materials for applications in the next generation flexible nanoelectronics. The construction of depletion region near the in-plane interface brings rich opto-electrical dynamics, which is essential for future applications. Due to the synchronous requirement of spatial and time resolution, the study of lateral heterojunction dynamics remains a challenging issue. Herein, with a home-built spatiotemporal femtosecond transient absorption (TAS) spectroscopy platform, we have investigated the ultrafast photocarrier dynamics of monolayer spatial composition-graded WS2xSe2(1-x) lateral heterojunctions. At the alloy interface, the charge transfer (CT) processes have been visualized and referred to occur in 1 ps time scale. The mobility difference between electrons and holes results in the space modulation of the interface and a significant broadening of rising edge on the shell region. Moreover, carrier lifetime near the interface is extraordinarily extended by over 3 times from 153 ps to 678 ps. All these results unveil its great potential in designing future low cost logic devices and ultrafast optical applications.
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Davoodi F, Granpayeh N. Near-infrared absorbers based on the heterostructures of two-dimensional materials. APPLIED OPTICS 2018; 57:1358-1366. [PMID: 29469834 DOI: 10.1364/ao.57.001358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 01/16/2018] [Indexed: 06/08/2023]
Abstract
Although the conductance and dielectric function of graphene can be tuned by applying external voltage, the tunability is less than 3%. Hybridizing graphene with other two-dimensional transition metal dichalcogenides (TMDs) can improve the adjustability and tunability of the optical properties of graphene-based structures at near-infrared frequencies. In this paper, we theoretically compute the dielectric function of graphene-MoTe2-graphene and graphene-MoTe2-graphene heterostructures utilizing the quantum electrostatic heterostructure (QEH) model, which is an ab-initio method. Utilizing the QEH results, we propose a hyper crystal (HC) absorber at near-infrared frequencies. Hence, we use the transfer matrix method to investigate our proposed absorber analytically. Moreover, we simulate the graphene-TMD-graphene (G-TMD-G) absorbers by the numerical finite difference time domain method. The results of the numerical solution are consistent with those of the analytical method. Due to the dependency of the Fermi level of graphene on the direct bandgap of the TMDs, the dielectric function of the G-TMD-G heterostructure can be tuned and enhanced further by changing the number of TMD layers. Finally, we demonstrate that the full absorption of the heterostructures can be achieved at different frequencies for transverse magnetic polarization. Since the thicknesses of the layers in the HC are lower than the wavelength of the light, no diffracted bands are ubiquitous, and the absorption can be observed for a wide range of incidence angles and bandwidths at near-infrared frequencies. Because of utilizing graphene-based HCs, in addition to the feasibility of design compared to the complex metasurfaces, the absorption bandwidth is significant for a wide range of incidence angles. This kind of HC absorber can be used in the design of sensitive optical devices, such as tunable filters, detectors, and photovoltaic applications.
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