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

Title: Giant spin-splitting and gap renormalization driven by trions in single-layer WS2/h-BN heterostructures

Abstract

In two-dimensional (2D) semiconducting transition metal dichalcogenides (TMDs), new electronic phenomena such as tunable bandgaps and strongly bound excitons and trions emerge from strong many-body effects, beyond the spin and valley degrees of freedom induced by spin-orbit coupling and by lattice symmetry. Combining single-layer TMDs with other 2D materials in van der Waals heterostructures offers an intriguing means of controlling the electronic properties through these many-body effects, by means of engineered interlayer interactions. Here, we use micro-focused angle-resolved photoemission spectroscopy (microARPES) and in situ surface doping to manipulate the electronic structure of single-layer WS2 on hexagonal boron nitride (WS2/h-BN). Upon electron doping, we observe an unexpected giant renormalization of the spin-orbit splitting of the single-layer WS2 valence band, from 430 meV to 660 meV, together with a bandgap reduction of at least 325 meV, attributed to the formation of trionic quasiparticles. Furthermore, these findings suggest that the electronic, spintronic and excitonic properties are widely tunable in 2D TMD/h-BN heterostructures, as these are intimately linked to the quasiparticle dynamics of the materials.

Authors:
ORCiD logo [1]; ORCiD logo [2]; ORCiD logo [3]; ORCiD logo [3]; ORCiD logo [4];  [1];  [1]; ORCiD logo [4]; ORCiD logo [1];  [3]; ORCiD logo [3]; ORCiD logo [3]
  1. The Ohio State Univ., Columbus, OH (United States)
  2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Aarhus Univ., Aarhus C (Denmark)
  3. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  4. Naval Research Lab., Washington, D.C. (United States)
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1462967
Grant/Contract Number:  
AC02-05CH11231
Resource Type:
Accepted Manuscript
Journal Name:
Nature Physics
Additional Journal Information:
Journal Volume: 14; Journal Issue: 4; Related Information: © 2017 The Author(s).; Journal ID: ISSN 1745-2473
Publisher:
Nature Publishing Group (NPG)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS

Citation Formats

Katoch, Jyoti, Ulstrup, Soren, Koch, Roland J., Moser, Simon, McCreary, Kathleen M., Singh, Simranjeet, Xu, Jinsong, Jonker, Berend T., Kawakami, Roland K., Bostwick, Aaron, Rotenberg, Eli, and Jozwiak, Chris. Giant spin-splitting and gap renormalization driven by trions in single-layer WS2/h-BN heterostructures. United States: N. p., 2018. Web. doi:10.1038/s41567-017-0033-4.
Katoch, Jyoti, Ulstrup, Soren, Koch, Roland J., Moser, Simon, McCreary, Kathleen M., Singh, Simranjeet, Xu, Jinsong, Jonker, Berend T., Kawakami, Roland K., Bostwick, Aaron, Rotenberg, Eli, & Jozwiak, Chris. Giant spin-splitting and gap renormalization driven by trions in single-layer WS2/h-BN heterostructures. United States. doi:10.1038/s41567-017-0033-4.
Katoch, Jyoti, Ulstrup, Soren, Koch, Roland J., Moser, Simon, McCreary, Kathleen M., Singh, Simranjeet, Xu, Jinsong, Jonker, Berend T., Kawakami, Roland K., Bostwick, Aaron, Rotenberg, Eli, and Jozwiak, Chris. Mon . "Giant spin-splitting and gap renormalization driven by trions in single-layer WS2/h-BN heterostructures". United States. doi:10.1038/s41567-017-0033-4. https://www.osti.gov/servlets/purl/1462967.
@article{osti_1462967,
title = {Giant spin-splitting and gap renormalization driven by trions in single-layer WS2/h-BN heterostructures},
author = {Katoch, Jyoti and Ulstrup, Soren and Koch, Roland J. and Moser, Simon and McCreary, Kathleen M. and Singh, Simranjeet and Xu, Jinsong and Jonker, Berend T. and Kawakami, Roland K. and Bostwick, Aaron and Rotenberg, Eli and Jozwiak, Chris},
abstractNote = {In two-dimensional (2D) semiconducting transition metal dichalcogenides (TMDs), new electronic phenomena such as tunable bandgaps and strongly bound excitons and trions emerge from strong many-body effects, beyond the spin and valley degrees of freedom induced by spin-orbit coupling and by lattice symmetry. Combining single-layer TMDs with other 2D materials in van der Waals heterostructures offers an intriguing means of controlling the electronic properties through these many-body effects, by means of engineered interlayer interactions. Here, we use micro-focused angle-resolved photoemission spectroscopy (microARPES) and in situ surface doping to manipulate the electronic structure of single-layer WS2 on hexagonal boron nitride (WS2/h-BN). Upon electron doping, we observe an unexpected giant renormalization of the spin-orbit splitting of the single-layer WS2 valence band, from 430 meV to 660 meV, together with a bandgap reduction of at least 325 meV, attributed to the formation of trionic quasiparticles. Furthermore, these findings suggest that the electronic, spintronic and excitonic properties are widely tunable in 2D TMD/h-BN heterostructures, as these are intimately linked to the quasiparticle dynamics of the materials.},
doi = {10.1038/s41567-017-0033-4},
journal = {Nature Physics},
number = 4,
volume = 14,
place = {United States},
year = {2018},
month = {1}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 15 works
Citation information provided by
Web of Science

Figures / Tables:

Fig. 1 Fig. 1: Spatially-resolved electronic structure mapping of a WS2/h-BN heterostructure supported on TiO2. a, Side-view sketch of WS2/h-BN on TiO2, illustrating SL WS2 regions contacted directly to h-BN and to TiO2. b, Optical microscope image of the sample. The contrast has been strongly enhanced to better visualize the SL WS2.more » Brown patches correspond to bare TiO2, light purple to WS2/TiO2 and the darker green/red structure is the h-BN flake. c, Spatial map of photoemission intensity (integrated over the red box in (d)) for the same region seen in b. See Supplementary Section 1 for details on the spatial intensity variations. d, Measured dispersion along the $ \overline{K}\ \overline{Γ}\ \overline{K'}\ $ direction of the SL WS2 BZ (see green BZ and dashed red line in the insert) collected at the spatial coordinates marked by a white arrow in c. The rectangular red box marks a region with crossing WS2 and h-BN bands where the photoemission intensity is integrated to produce the spatial map in c. e, ARPES dispersion in the high symmetry direction of h-BN (see purple BZ and dashed black line in the insert). f-h, Constant energy cuts obtained at the given binding energies (see also ticks on the right of panels d-e). Arrows mark distinct energy contours relating to SL WS2 and to h-BN. The red and black dashed lines (insert in d-e) indicate a twist angle of (23 ± 1)° in between the SL WS2 and h-BN. i-j, EDCs obtained along the dotted lines in d-e around the h-BN VBM (i) and SL WS2 VBM (j). The positions of the band edges are given in units of eV and the error bar is 30 meV.« less

Save / Share:

Works referenced in this record:

Coupled Spin and Valley Physics in Monolayers of MoS 2 and Other Group-VI Dichalcogenides
journal, May 2012


Direct Measurement of the Thickness-Dependent Electronic Band Structure of MoS 2 Using Angle-Resolved Photoemission Spectroscopy
journal, September 2013


Negative electronic compressibility and tunable spin splitting in WSe2
journal, September 2015

  • Riley, J. M.; Meevasana, W.; Bawden, L.
  • Nature Nanotechnology, Vol. 10, Issue 12
  • DOI: 10.1038/nnano.2015.217

Direct observation of the transition from indirect to direct bandgap in atomically thin epitaxial MoSe2
journal, December 2013


Spatially Resolved Electronic Properties of Single-Layer WS 2 on Transition Metal Oxides
journal, October 2016


Gaps induced by inversion symmetry breaking and second-generation Dirac cones in graphene/hexagonal boron nitride
journal, August 2016

  • Wang, Eryin; Lu, Xiaobo; Ding, Shijie
  • Nature Physics, Vol. 12, Issue 12
  • DOI: 10.1038/nphys3856

Van der Waals heterostructures
journal, July 2013

  • Geim, A. K.; Grigorieva, I. V.
  • Nature, Vol. 499, Issue 7459, p. 419-425
  • DOI: 10.1038/nature12385

Spin and pseudospins in layered transition metal dichalcogenides
journal, April 2014

  • Xu, Xiaodong; Yao, Wang; Xiao, Di
  • Nature Physics, Vol. 10, Issue 5
  • DOI: 10.1038/nphys2942

Electronic Structure, Surface Doping, and Optical Response in Epitaxial WSe 2 Thin Films
journal, March 2016


Photonics and optoelectronics of 2D semiconductor transition metal dichalcogenides
journal, March 2016


Exciton Binding Energy of Monolayer WS2
journal, March 2015

  • Zhu, Bairen; Chen, Xi; Cui, Xiaodong
  • Scientific Reports, Vol. 5, Issue 1
  • DOI: 10.1038/srep09218

Population inversion and giant bandgap renormalization in atomically thin WS2 layers
journal, June 2015


Corrigendum: k.p theory for two-dimensional transition metal dichalcogenide semiconductors (2015 2D Mater. 2 022001)
journal, November 2015


Universal Mechanism of Band-Gap Engineering in Transition-Metal Dichalcogenides
journal, February 2017


Band Offset and Negative Compressibility in Graphene-MoS 2 Heterostructures
journal, March 2014

  • Larentis, Stefano; Tolsma, John R.; Fallahazad, Babak
  • Nano Letters, Vol. 14, Issue 4
  • DOI: 10.1021/nl500212s

Electrical Tuning of Exciton Binding Energies in Monolayer WS 2
journal, September 2015


Carrier Plasmon Induced Nonlinear Band Gap Renormalization in Two-Dimensional Semiconductors
journal, February 2015


One-Dimensional Electrical Contact to a Two-Dimensional Material
journal, October 2013


Optical Spectrum of MoS 2 : Many-Body Effects and Diversity of Exciton States
journal, November 2013


Tightly bound trions in monolayer MoS2
journal, December 2012

  • Mak, Kin Fai; He, Keliang; Lee, Changgu
  • Nature Materials, Vol. 12, Issue 3
  • DOI: 10.1038/nmat3505

Electronic Structure of Epitaxial Single-Layer MoS 2
journal, January 2015


Many-body theory of trion absorption features in two-dimensional semiconductors
journal, January 2017


Quasiparticle dynamics in graphene
journal, December 2006

  • Bostwick, Aaron; Ohta, Taisuke; Seyller, Thomas
  • Nature Physics, Vol. 3, Issue 1
  • DOI: 10.1038/nphys477

Effective tight-binding model for M X 2 under electric and magnetic fields
journal, June 2015


Growth and electronic structure of epitaxial single-layer WS 2 on Au(111)
journal, December 2015


Boron nitride substrates for high-quality graphene electronics
journal, August 2010

  • Dean, C. R.; Young, A. F.; Meric, I.
  • Nature Nanotechnology, Vol. 5, Issue 10, p. 722-726
  • DOI: 10.1038/nnano.2010.172

Large conduction band and Fermi velocity spin splitting due to Coulomb interactions in single-layer MoS 2
journal, November 2014


Large excitonic effects in monolayers of molybdenum and tungsten dichalcogenides
journal, September 2012


Giant bandgap renormalization and excitonic effects in a monolayer transition metal dichalcogenide semiconductor
journal, August 2014

  • Ugeda, Miguel M.; Bradley, Aaron J.; Shi, Su-Fei
  • Nature Materials, Vol. 13, Issue 12
  • DOI: 10.1038/nmat4061

Zeeman-type spin splitting controlled by an electric field
journal, July 2013

  • Yuan, Hongtao; Bahramy, Mohammad Saeed; Morimoto, Kazuhiro
  • Nature Physics, Vol. 9, Issue 9
  • DOI: 10.1038/nphys2691

    Works referencing / citing this record:

    Direct Determination of Band-Gap Renormalization in the Photoexcited Monolayer MoS 2
    journal, June 2019


    Giant gate-tunable bandgap renormalization and excitonic effects in a 2D semiconductor
    journal, July 2019


    Direct Determination of Band-Gap Renormalization in the Photoexcited Monolayer MoS 2
    journal, June 2019


    Giant gate-tunable bandgap renormalization and excitonic effects in a 2D semiconductor
    journal, July 2019


      Figures/Tables have been extracted from DOE-funded journal article accepted manuscripts.