skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Moiré potential impedes interlayer exciton diffusion in van der Waals heterostructures

Abstract

The properties of van der Waals heterostructures are drastically altered by a tunable moiré superlattice arising from periodically varying atomic alignment between the layers. Exciton diffusion represents an important channel of energy transport in transition metal dichalcogenides (TMDs). While early studies performed on TMD heterobilayers suggested that carriers and excitons exhibit long diffusion, a rich variety of scenarios can exist. In a moiré crystal with a large supercell and deep potential, interlayer excitons may be completely localized. As the moiré period reduces at a larger twist angle, excitons can tunnel between supercells and diffuse over a longer lifetime. The diffusion should be the longest in commensurate heterostructures where the moiré superlattice is completely absent. Here, we experimentally demonstrate the rich phenomena of interlayer exciton diffusion in WSe 2 /MoSe 2 heterostructures by comparing several samples prepared with chemical vapor deposition and mechanical stacking with accurately controlled twist angles.

Authors:
ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [2];  [1];  [2];  [3];  [1];  [1];  [4]; ORCiD logo [1];  [1];  [5]; ORCiD logo [5];  [3]; ORCiD logo [6];  [7]; ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [8]
  1. Department of Physics, Complex Quantum Systems, and Texas Materials Institute, The University of Texas at Austin, Austin, TX 78712, USA.
  2. Department of Electrophysics, National Chiao Tung University, Hsinchu 30010, Taiwan.
  3. Center for Condensed Matter Sciences, National Taiwan University, Taipei 10617, Taiwan.
  4. Department of Physics, Complex Quantum Systems, and Texas Materials Institute, The University of Texas at Austin, Austin, TX 78712, USA., Department of Physics, National Tsing-Hua University, Hsinchu 30013, Taiwan., Research Center for Applied Sciences, Academia Sinica, Nankang, Taipei 11529, Taiwan.
  5. National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
  6. Department of Physics, National Tsing-Hua University, Hsinchu 30013, Taiwan., Research Center for Applied Sciences, Academia Sinica, Nankang, Taipei 11529, Taiwan.
  7. Department of Photonics and Nanoelectronics, Hanyang University, Ansan 15588, Republic of Korea.
  8. Department of Electrophysics, National Chiao Tung University, Hsinchu 30010, Taiwan., Center for Emergent Functional Matter Science (CEFMS), National Chiao Tung University, Hsinchu 30010, Taiwan.
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1664585
Grant/Contract Number:  
SC0019398
Resource Type:
Published Article
Journal Name:
Science Advances
Additional Journal Information:
Journal Name: Science Advances Journal Volume: 6 Journal Issue: 39; Journal ID: ISSN 2375-2548
Publisher:
American Association for the Advancement of Science (AAAS)
Country of Publication:
United States
Language:
English

Citation Formats

Choi, Junho, Hsu, Wei-Ting, Lu, Li-Syuan, Sun, Liuyang, Cheng, Hui-Yu, Lee, Ming-Hao, Quan, Jiamin, Tran, Kha, Wang, Chun-Yuan, Staab, Matthew, Jones, Kayleigh, Taniguchi, Takashi, Watanabe, Kenji, Chu, Ming-Wen, Gwo, Shangjr, Kim, Suenne, Shih, Chih-Kang, Li, Xiaoqin, and Chang, Wen-Hao. Moiré potential impedes interlayer exciton diffusion in van der Waals heterostructures. United States: N. p., 2020. Web. https://doi.org/10.1126/sciadv.aba8866.
Choi, Junho, Hsu, Wei-Ting, Lu, Li-Syuan, Sun, Liuyang, Cheng, Hui-Yu, Lee, Ming-Hao, Quan, Jiamin, Tran, Kha, Wang, Chun-Yuan, Staab, Matthew, Jones, Kayleigh, Taniguchi, Takashi, Watanabe, Kenji, Chu, Ming-Wen, Gwo, Shangjr, Kim, Suenne, Shih, Chih-Kang, Li, Xiaoqin, & Chang, Wen-Hao. Moiré potential impedes interlayer exciton diffusion in van der Waals heterostructures. United States. https://doi.org/10.1126/sciadv.aba8866
Choi, Junho, Hsu, Wei-Ting, Lu, Li-Syuan, Sun, Liuyang, Cheng, Hui-Yu, Lee, Ming-Hao, Quan, Jiamin, Tran, Kha, Wang, Chun-Yuan, Staab, Matthew, Jones, Kayleigh, Taniguchi, Takashi, Watanabe, Kenji, Chu, Ming-Wen, Gwo, Shangjr, Kim, Suenne, Shih, Chih-Kang, Li, Xiaoqin, and Chang, Wen-Hao. Wed . "Moiré potential impedes interlayer exciton diffusion in van der Waals heterostructures". United States. https://doi.org/10.1126/sciadv.aba8866.
@article{osti_1664585,
title = {Moiré potential impedes interlayer exciton diffusion in van der Waals heterostructures},
author = {Choi, Junho and Hsu, Wei-Ting and Lu, Li-Syuan and Sun, Liuyang and Cheng, Hui-Yu and Lee, Ming-Hao and Quan, Jiamin and Tran, Kha and Wang, Chun-Yuan and Staab, Matthew and Jones, Kayleigh and Taniguchi, Takashi and Watanabe, Kenji and Chu, Ming-Wen and Gwo, Shangjr and Kim, Suenne and Shih, Chih-Kang and Li, Xiaoqin and Chang, Wen-Hao},
abstractNote = {The properties of van der Waals heterostructures are drastically altered by a tunable moiré superlattice arising from periodically varying atomic alignment between the layers. Exciton diffusion represents an important channel of energy transport in transition metal dichalcogenides (TMDs). While early studies performed on TMD heterobilayers suggested that carriers and excitons exhibit long diffusion, a rich variety of scenarios can exist. In a moiré crystal with a large supercell and deep potential, interlayer excitons may be completely localized. As the moiré period reduces at a larger twist angle, excitons can tunnel between supercells and diffuse over a longer lifetime. The diffusion should be the longest in commensurate heterostructures where the moiré superlattice is completely absent. Here, we experimentally demonstrate the rich phenomena of interlayer exciton diffusion in WSe 2 /MoSe 2 heterostructures by comparing several samples prepared with chemical vapor deposition and mechanical stacking with accurately controlled twist angles.},
doi = {10.1126/sciadv.aba8866},
journal = {Science Advances},
number = 39,
volume = 6,
place = {United States},
year = {2020},
month = {9}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
https://doi.org/10.1126/sciadv.aba8866

Save / Share:

Works referenced in this record:

Moiré excitons: From programmable quantum emitter arrays to spin-orbit–coupled artificial lattices
journal, November 2017


Quantum diffusion of dipole-oriented indirect excitons in coupled quantum wells
journal, August 2002


Optical properties of pyrolytic boron nitride in the energy range 0.05—10 eV
journal, November 1984


Exciton diffusion in WSe 2 monolayers embedded in a van der Waals heterostructure
journal, April 2018

  • Cadiz, F.; Robert, C.; Courtade, E.
  • Applied Physics Letters, Vol. 112, Issue 15
  • DOI: 10.1063/1.5026478

Exciton Diffusion and Halo Effects in Monolayer Semiconductors
journal, May 2018


Band offsets and heterostructures of two-dimensional semiconductors
journal, January 2013

  • Kang, Jun; Tongay, Sefaattin; Zhou, Jian
  • Applied Physics Letters, Vol. 102, Issue 1
  • DOI: 10.1063/1.4774090

Nonlinear dynamics of a dense two-dimensional dipolar exciton gas
journal, January 2006


Unconventional superconductivity in magic-angle graphene superlattices
journal, March 2018


Gate-induced superconductivity in atomically thin MoS2 crystals
journal, January 2016

  • Costanzo, Davide; Jo, Sanghyun; Berger, Helmuth
  • Nature Nanotechnology, Vol. 11, Issue 4
  • DOI: 10.1038/nnano.2015.314

Full superconducting dome of strong Ising protection in gated monolayer WS 2
journal, March 2018

  • Lu, Jianming; Zheliuk, Oleksandr; Chen, Qihong
  • Proceedings of the National Academy of Sciences, Vol. 115, Issue 14
  • DOI: 10.1073/pnas.1716781115

Valley-polarized exciton currents in a van der Waals heterostructure
journal, October 2019

  • Unuchek, Dmitrii; Ciarrocchi, Alberto; Avsar, Ahmet
  • Nature Nanotechnology, Vol. 14, Issue 12
  • DOI: 10.1038/s41565-019-0559-y

Tunable moiré bands and strong correlations in small-twist-angle bilayer graphene
journal, March 2017

  • Kim, Kyounghwan; DaSilva, Ashley; Huang, Shengqiang
  • Proceedings of the National Academy of Sciences, Vol. 114, Issue 13
  • DOI: 10.1073/pnas.1620140114

Exciton Dynamics, Transport, and Annihilation in Atomically Thin Two-Dimensional Semiconductors
journal, July 2017


Theory of optical absorption by interlayer excitons in transition metal dichalcogenide heterobilayers
journal, January 2018


Moiré Intralayer Excitons in a MoSe 2 /MoS 2 Heterostructure
journal, November 2018


Hofstadter’s butterfly and the fractal quantum Hall effect in moiré superlattices
journal, May 2013


Vertical and in-plane heterostructures from WS2/MoS2 monolayers
journal, September 2014

  • Gong, Yongji; Lin, Junhao; Wang, Xingli
  • Nature Materials, Vol. 13, Issue 12, p. 1135-1142
  • DOI: 10.1038/nmat4091

Signatures of moiré-trapped valley excitons in MoSe2/WSe2 heterobilayers
journal, February 2019


High-temperature superfluidity with indirect excitons in van der Waals heterostructures
journal, July 2014

  • Fogler, M. M.; Butov, L. V.; Novoselov, K. S.
  • Nature Communications, Vol. 5, Issue 1
  • DOI: 10.1038/ncomms5555

Valley-polarized exciton dynamics in a 2D semiconductor heterostructure
journal, February 2016


Evidence for moiré excitons in van der Waals heterostructures
journal, February 2019


Observation of moiré excitons in WSe2/WS2 heterostructure superlattices
journal, February 2019


Second Harmonic Generation from Artificially Stacked Transition Metal Dichalcogenide Twisted Bilayers
journal, February 2014

  • Hsu, Wei-Ting; Zhao, Zi-Ang; Li, Lain-Jong
  • ACS Nano, Vol. 8, Issue 3
  • DOI: 10.1021/nn500228r

Electronic properties of the MoS 2 -WS 2 heterojunction
journal, February 2013


Imaging of pure spin-valley diffusion current in WS 2 -WSe 2 heterostructures
journal, May 2018


Fast pick up technique for high quality heterostructures of bilayer graphene and hexagonal boron nitride
journal, July 2014

  • Zomer, P. J.; Guimarães, M. H. D.; Brant, J. C.
  • Applied Physics Letters, Vol. 105, Issue 1
  • DOI: 10.1063/1.4886096

Twist-angle-dependent interlayer exciton diffusion in WS2–WSe2 heterobilayers
journal, May 2020


Negative circular polarization emissions from WSe2/MoSe2 commensurate heterobilayers
journal, April 2018


Correlated insulator behaviour at half-filling in magic-angle graphene superlattices
journal, March 2018


Dielectric disorder in two-dimensional materials
journal, August 2019


Density Enhanced Diffusion of Dipolar Excitons within a One-Dimensional Channel
journal, September 2009


Determination of band alignment in the single-layer MoS2/WSe2 heterojunction
journal, July 2015

  • Chiu, Ming-Hui; Zhang, Chendong; Shiu, Hung-Wei
  • Nature Communications, Vol. 6, Issue 1
  • DOI: 10.1038/ncomms8666

Monolayer MoSe 2 Grown by Chemical Vapor Deposition for Fast Photodetection
journal, July 2014

  • Chang, Yung-Huang; Zhang, Wenjing; Zhu, Yihan
  • ACS Nano, Vol. 8, Issue 8
  • DOI: 10.1021/nn503287m

Van der Waals heterostructures and devices
journal, July 2016


Anomalous Light Cones and Valley Optical Selection Rules of Interlayer Excitons in Twisted Heterobilayers
journal, October 2015


Long-Lived Direct and Indirect Interlayer Excitons in van der Waals Heterostructures
journal, August 2017


Room-temperature electrical control of exciton flux in a van der Waals heterostructure
journal, July 2018


Electrical control of interlayer exciton dynamics in atomically thin heterostructures
journal, November 2019

  • Jauregui, Luis A.; Joe, Andrew Y.; Pistunova, Kateryna
  • Science, Vol. 366, Issue 6467
  • DOI: 10.1126/science.aaw4194

Second harmonic microscopy of monolayer MoS 2
journal, April 2013


Probing Symmetry Properties of Few-Layer MoS 2 and h-BN by Optical Second-Harmonic Generation
journal, June 2013

  • Li, Yilei; Rao, Yi; Mak, Kin Fai
  • Nano Letters, Vol. 13, Issue 7
  • DOI: 10.1021/nl401561r

Theory of two-dimensional spatially indirect equilibrium exciton condensates
journal, October 2015


Giant magnetic splitting inducing near-unity valley polarization in van der Waals heterostructures
journal, November 2017

  • Nagler, Philipp; Ballottin, Mariana V.; Mitioglu, Anatolie A.
  • Nature Communications, Vol. 8, Issue 1
  • DOI: 10.1038/s41467-017-01748-1

Large-Area Synthesis of Highly Crystalline WSe 2 Monolayers and Device Applications
journal, December 2013

  • Huang, Jing-Kai; Pu, Jiang; Hsu, Chang-Lung
  • ACS Nano, Vol. 8, Issue 1
  • DOI: 10.1021/nn405719x

Topological Exciton Bands in Moiré Heterojunctions
journal, April 2017


Measurement of the optical dielectric function of monolayer transition-metal dichalcogenides: MoS 2 , Mo S e 2 , WS 2 , and WS e 2
journal, November 2014


Observation of intense second harmonic generation from MoS 2 atomic crystals
journal, May 2013

  • Malard, Leandro M.; Alencar, Thonimar V.; Barboza, Ana Paula M.
  • Physical Review B, Vol. 87, Issue 20
  • DOI: 10.1103/PhysRevB.87.201401

Observation of long-lived interlayer excitons in monolayer MoSe2–WSe2 heterostructures
journal, February 2015

  • Rivera, Pasqual; Schaibley, John R.; Jones, Aaron M.
  • Nature Communications, Vol. 6, Issue 1
  • DOI: 10.1038/ncomms7242

Interlayer couplings, Moiré patterns, and 2D electronic superlattices in MoS 2 /WSe 2 hetero-bilayers
journal, January 2017