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Stacking-induced direct band gap in CVD-grown 1H MoS<sub>2</sub> bilayers

Nature作者：Tilo H. Yang2026年9月23日正文已收录本站

Data availability

All data needed to evaluate the conclusions are presented in the Article and the Supplementary Information. Additional data are available from the corresponding authors upon request. Source data are provided with this paper.

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Acknowledgements

We express our gratitude to the staff members, specially for C.-M. Cheng and P.-H. Lin, of the National Synchrotron Radiation Research Center for their support and assistance with the experiments conducted at the Taiwan Photon Source (TPS) 39A1 beamline and TPS 27A2—Photoelectron Related Image and Nano-Spectroscopy. This work was also partially supported by the Taiwan Semiconductor Research Institute for the device fabrication, the Instrumentation Center at National Tsing Hua University for the STEM experiments and the Semiconductor Fabrication Lab of the Consortia of Key Technologies, and the Nano-Electro-Mechanical-System Research Center, National Taiwan University. We appreciate the technical support for HR-STEM and facility optimization provided by P.-H. Chiu at the Instrumentation Center, National Taiwan University. We also acknowledge the support from the Chem-Scitech International Company, Molsentech, NANYTE (Singapore) and i-Wavefront Technology through the industry–academia collaboration that made this research possible.

Funding

This work was supported by the National Science and Technology Council (NSTC), Taiwan, under grant nos. MOST 111-2628-M-003-002-MY3 (Y.-W.L.), MOST 111-2124-M-003-005 (Y.-W.L.), NSTC 112-2124-M-003-002 (Y.-W.L.), NSTC 114-2112-M-003-017-MY3 (Y.-W.L.), NSTC 115-2640-M-003-002 (Y.-W.L.), MOST 111-2124-M-006-001 (K.-I.L.), NSTC 113-2112-M-006-031 (K.-I.L.), NSTC 114-2112-M-006-032 (K.-I.L.), NSTC 115-2112-M-006-026 (K.-I.L.), NSTC 112-2112-M-003-014 (T.-H.L.) and NSTC 114-2628-M-003-001-MY3 (T.-H.L.). This research was also supported by the ‘Spin-valleytronics Based on Low-Dimensional Materials’ programme under the University Academic Alliance in Taiwan, funded by the Ministry of Education (MoE) and by the Higher Education Sprout Project of National Taiwan Normal University and the MoE, Taiwan. Partial support was provided by the Postdoctoral Research Abroad Program of the NSTC under grant no. 112-2917-I-564-010 (T.H.Y.). T.H.Y. and J.K. also acknowledge support from the Semiconductor Research Corporation Center 7 in JUMP 2.0 under award no. 145105-21913 and the National Science Foundation under award no. 2527588. H.-W.Y., Y.-C.C. and H.-Y.L. acknowledge support from the NSTC under grant nos. 115-2640-M-007-001, 115-2628-E-002-009 and 115-2740-M-002-007. S.-Y.C. acknowledges support from the NSTC under grant nos. 114-2628-M-002-004 and 115-2628-M-002-014, and from the MoE under grant nos. 114 L9008, 115 L9008, 114V1050-2 and 115V1050-3. T.-H.C. acknowledges support from the NSTC under grant no. 114-2112-M-213-022. D.-H.W. and M.-C.W. acknowledge support from the NSTC under grant no. 113-2112-M-213-022.

Author information

Author notes

  1. Vo Khuong Dien

    Present address: College of Natural Sciences, Can Tho University, Can Tho, Vietnam

Authors and Affiliations

  1. Department of Physics, National Taiwan Normal University, Taipei, Taiwan

    Tilo H. Yang, I-Tong Chen, Min-Jia Zhang, Ju-Yi Huang, Tzu-Hao Kuo, Ting-Hua Lu & Yann-Wen Lan

  2. Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA

    Tilo H. Yang, Zachariah B. Hennighausen & Jing Kong

  3. Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA

    Tilo H. Yang, Zachariah B. Hennighausen & Jing Kong

  4. Center for Condensed Matter Sciences, National Taiwan University, Taipei, Taiwan

    Shao-Yu Chen

  5. Center of Atomic Initiative for New Materials, National Taiwan University, Taipei, Taiwan

    Shao-Yu Chen

  6. Institute of Physics, National Yang Ming Chiao Tung University, Hsinchu, Taiwan

    Shao-Yu Chen

  7. Graduate School of Advanced Technology, National Taiwan University, Taipei, Taiwan

    Hsing-Yeh Li

  8. Department of Materials Science and Engineering, National Taiwan University, Taipei, Taiwan

    Ying-Chun Chao & Hung-Wei Yen

  9. Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu, Taiwan

    Vo Khuong Dien

  10. National Synchrotron Radiation Research Center, Hsinchu, Taiwan

    Heng-Wen Wei, Meng-Che Wu, Tzu-Hung Chuang & Der-Hsin Wei

  11. Core Facility Center, National Cheng Kung University, Tainan, Taiwan

    Kuang-I Lin

  12. Program on Key Materials, Academy of Innovative Semiconductor and Sustainable Manufacturing, National Cheng Kung University, Tainan, Taiwan

    Kuang-I Lin

Authors

  1. Tilo H. Yang
  2. I-Tong Chen
  3. Min-Jia Zhang
  4. Ju-Yi Huang
  5. Tzu-Hao Kuo
  6. Shao-Yu Chen
  7. Hsing-Yeh Li
  8. Ying-Chun Chao
  9. Zachariah B. Hennighausen
  10. Vo Khuong Dien
  11. Heng-Wen Wei
  12. Meng-Che Wu
  13. Hung-Wei Yen
  14. Tzu-Hung Chuang
  15. Der-Hsin Wei
  16. Jing Kong
  17. Ting-Hua Lu
  18. Kuang-I Lin
  19. Yann-Wen Lan

Contributions

T.H.Y., T.-H.L., K.-I.L. and Y.-W.L. conceived the idea and devised the project. T.H.Y., I.-T.C. and M.-J.Z. conducted the material growth. T.H.Y., I.-T.C., J.-Y.H., T.-H.L. and M.-J.Z. performed Raman, PL, circular dichroism and AFM measurements. T.H.Y., I.-T.C., J.-Y.H., M.-J.Z., T.-H.K. and K.-I.L. conducted data analysis and graphical visualization. T.H.Y. performed STEM and SADP analysis and simulations. T.H.Y. derived crystallographic identification and examined the validity and interpretation of the experimental results. M.-J.Z. and S.-Y.C. collected and analysed absorption spectra. K.-I.L. collected and analysed SHG images. I.-T.C., J.-Y.H., M.-J.Z. and T.-H.K. prepared samples for ARPES investigation. H.-W.W., M.-C.W., T.-H.C. and D.-H.W. conducted ARPES measurements and analysed the data. Z.B.H. conducted manual stacking and characterized the stacked samples. V.K.D. conducted DFT simulations on electronic band structures. H.-Y.L. collected part of the STEM images and SADPs and assisted with the analysis. H.-Y.L., Y.-C.C. and H.-W.Y. performed FIB to prepare cross-sectional samples and acquired cross-sectional STEM images. T.H.Y. and K.-I.L. wrote the manuscript after detailed discussion with all authors. J.K., T.-H.L. and Y.-W.L. revised the manuscript. Y.-W.L. supervised the overall project. All authors read and approved of the manuscript.

Corresponding authors

Correspondence to Tilo H. Yang, Ting-Hua Lu, Kuang-I Lin or Yann-Wen Lan.

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Extended data figures and tables

Extended Data Fig. 1 Two-step chemical vapour deposition process and growth mechanism for 1H, 3R, and 2H MoS2 bilayers.

a, Experimental setup for the modified two-step CVD process. b, Growth temperature modulation and representative optical images of the as-grown MoS2 flakes: (I) 1H, (II) 3R, and (III) 2H. c, Schematic illustrating the surface and edge diffusion of a Mo adatom on a monolayer MoS2 surface with 1H and 3R stacking, respectively. Migration pathways atop Mo sites are indicated by blue arrows, representing sequential hopping events along equivalent \(\langle \bar{1}\,2\,\bar{1}\,0\rangle \) directions. Shaded areas highlight the distinct development processes of edge and surface diffusion. d, Arrhenius plot of the hopping rate ratio (RD = Γs/Γe), where Γs and Γe represent the hopping rates of a Mo adatom for surface and edge diffusion, respectively. e, Optical micrograph showing the formation of six primary ribbons with preferred orientations along the \(\langle \bar{1}\,2\,\bar{1}\,0\rangle \) directions, with multiple secondary ribbons branching before coalescing into 1H MoS2 bilayer triangles. See also Extended Data Fig. 3.

Extended Data Fig. 2 Optical, second-harmonic generation (SHG), and atomic force microscopy (AFM) characterizations of MoS2 polytypic bilayers.

a-c, Representative optical images of the as-grown 1H, 3R, and 2H stacked MoS2 flakes, respectively. d-f, Representative SHG images of the corresponding flakes. g-i, Representative AFM surface morphology images of the corresponding flakes.

Extended Data Fig. 3 Seamless merging of adjacent 1H MoS2 bilayer ribbons.

a, Low-magnification bright-field TEM image showing the unidirectional alignment of bilayer nanoribbons. b, Fully stitched bilayer observed in bright-field TEM. c,d, Enlarged dark-field TEM images, revealing the seamless stitching region of two adjacent bilayer ribbons.

Extended Data Fig. 4 HAADF-STEM imaging and SADP characterization of 1H-stacked bilayer MoS2.

a,b, BF-TEM images of bilayer MoS2. c,d, HAADF-STEM images and SADPs acquired from the marked regions in a and b, respectively. Line profiles were extracted along three directions (labelled 1–3) in each SADP.

Source data

Extended Data Fig. 5 Extended HAADF-STEM images of MoS2 bilayer regions.

The examined areas consistently exhibit the 1H stacking structure and demonstrate uniformity at the atomic scale. The raw images can be found in Supplementary Fig. 5a–d.

Extended Data Fig. 6 Cross-sectional HAADF-STEM images of bilayer MoS2.

a,b, Cross-sectional HAADF-STEM images of 1H- and 3R-stacked bilayer MoS2, respectively. c,d, High-pass-filtered images of a and b, respectively. The average interlayer spacing was determined by measuring the distances between parallel planes containing Mo atoms at ten different locations within the image, as summarized in Supplementary Table 2. e,f, Fast Fourier transform (FFT) images showing the corresponding diffractograms from c and d, respectively. g,h, Simulated SADPs under the [1 1 0] zone axis for 1H- and 3R-stacked MoS2, respectively.

Extended Data Fig. 7 Extended PL mappings of 1H bilayer and monolayer MoS2.

Each row displays, from left to right, an optical microscopy image, PL peak intensity mapping, PL position mapping, and the evolution of PL spectra along the blue arrow indicated in the PL peak intensity mapping.

Source data

Extended Data Fig. 8 Photoelectron momentum microscopy (MM) measurements on a 1H bilayer MoS2 sample.

a, MoS2/graphene/Si mounted on a sample plate for MM measurements. b, Optical microscopy (OM) of the yellow-circled region in a. Region 1 is graphene, and region 2 is MoS2 thin film, which is magnified by OM shown in c, and further magnified by photoemission electron microscope (PEEM) shown in d. e, Momentum images recorded from graphene area [Region 1 in b] at the Fermi energy (EF) and 1.65 eV below EF. f, ARPES spectrum obtained from graphene area along Γ-K direction extracted by stacking a series of momentum images measured at various kinetic energies, and slicing along two Dirac-points indicated as a red line in e. Two sets of Dirac-points rotated by 30 degree were found, possibly due to two graphene crystallographic orientations. g, Momentum images recorded from MoS2 area [Region 2 in b] at the EF and 1.65 eV below EF. h, ARPES spectrum obtained from MoS2 area extracted by stacking a series of momentum images measured at various kinetic energies, and slicing along the direction indicated in red in g. The 1H MoS2 bilayer flakes exhibit multiple crystallographic orientations shown in d, which contribute ring-like pattern at the high-symmetry position on the momentum images. Further analysis is presented in Extended Data Fig. 9.

Source data

Extended Data Fig. 9 Photoelectron MM analysis of a 1H bilayer MoS2 sample.

a, Red and blue triangles highlighted different crystallographic orientations of the 1H MoS2 flakes randomly distributed within the MM probing area. b, Momentum image recorded at the energy of 1.54 eV below the Fermi energy, and the ring-like pattern is attributed to multiple crystallographic orientations of the 1H MoS2 flakes. The ARPES spectra are obtained by slicing along 6 representative directions indicated in b, and presented in c with raw data, 1st derivative, and 2nd derivative in order to enhance the contrast. The energy distribution curves (EDC) along Γ- and K-points at various slicing angles are shown in d. e, Fitting results and the values of the valence band K2-Γ for 1H bilayer (blue background) and monolayer (yellow background) MoS2. All values for the 1H bilayer MoS2 indicate the presence of a direct bandgap. The value for the monolayer MoS2 (146 meV) is consistent with the literature57.

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Yang, T.H., Chen, IT., Zhang, MJ. et al. Stacking-induced direct band gap in CVD-grown 1H MoS2 bilayers. Nature (2026). https://doi.org/10.1038/s41586-026-11069-3

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