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Giant second-harmonic generation in ferroelectric NbOI2

Nature Photonics volume 16, pages 644–650 (2022)Cite this article

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Abstract

Implementing nonlinear optical components in nanoscale photonic devices is challenged by phase-matching conditions requiring thicknesses in the order of hundreds of wavelengths, and is disadvantaged by the short optical interaction depth of nanometre-scale materials and weak photon–photon interactions. Here we report that ferroelectric NbOI2 nanosheets exhibit giant second-harmonic generation with conversion efficiencies that are orders of magnitude higher than commonly reported nonlinear crystals. The nonlinear response scales with layer thickness and is strain- and electrical-tunable; a record >0.2% absolute SHG conversion efficiency and an effective nonlinear susceptibility \(\chi _{\mathrm{eff}}^{(2)}\) in the order of 10−9 m V−1 are demonstrated at an average pump intensity of 8 kW cm–2. Due to the interplay between anisotropic polarization and excitonic resonance in NbOI2, the spatial profile of the polarized SHG response can be tuned by the excitation wavelength. Our results represent a new paradigm for ultrathin, efficient nonlinear optical components.

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Fig. 1: Atomic structure of ferroelectric layered NbOI2.
Fig. 2: Anisotropic band structure and linear optical response of NbOI2.
Fig. 3: Characterization of SHG in NbOI2.
Fig. 4: Effects of strain, temperature and electric fields on SHG in NbOI2.

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Data availability

The data supporting the findings of this study are available within the article and its Supplementary Information, or from the corresponding authors on reasonable request. The X-ray crystallographic coordinates for structures reported in this study have been deposited at the Cambridge Crystallographic Data Centre (CCDC), under deposition nos. 2169918-2169919. These data can be obtained free of charge from the Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_request/cif.

References

  1. Boyd, R. W. Nonlinear Optics 3rd edn (Academic, 2008).

    Google Scholar 

  2. Helk, T. et al. Table-top extreme ultraviolet second harmonic generation. Sci. Adv. 7, eabe2265 (2021).

    Article  ADS  Google Scholar 

  3. Shwartz, S. et al. X-ray second harmonic generation. Phys. Rev. Lett. 112, 163901 (2014).

    Article  ADS  Google Scholar 

  4. Trebino, R. et al. Measuring ultrashort laser pulses in the time-frequency domain using frequency-resolved optical gating. Rev. Sci. Instrum. 68, 3277–3295 (1997).

    Article  ADS  Google Scholar 

  5. Willner, A. E., Khaleghi, S., Chitgarha, M. R. & Yilmaz, O. F. All-optical signal processing. J. Lightwave Technol. 32, 660–680 (2014).

    Article  ADS  Google Scholar 

  6. Pantazis, P., Maloney, J., Wu, D. & Fraser, S. E. Second harmonic generating (SHG) nanoprobes for in vivo imaging. Proc. Natl Acad. Sci. USA 107, 14535–14540 (2010).

    Article  ADS  Google Scholar 

  7. Manaka, T., Lim, E., Tamura, R. & Iwamoto, M. Direct imaging of carrier motion in organic transistors by optical second-harmonic generation. Nat. Photon. 1, 581–584 (2007).

    Article  ADS  Google Scholar 

  8. Yin, X. et al. Edge nonlinear optics on a MoS2 atomic monolayer. Science 344, 488–490 (2014).

    Article  ADS  Google Scholar 

  9. Shen, Y. Surface properties probed by second-harmonic and sum-frequency generation. Nature 337, 519–525 (1989).

    Article  ADS  Google Scholar 

  10. Hsieh, D. et al. Nonlinear optical probe of tunable surface electrons on a topological insulator. Phys. Rev. Lett. 106, 057401 (2011).

    Article  ADS  Google Scholar 

  11. Yakovlev, D. R. et al. Exciton spectroscopy of semiconductors by the method of optical harmonics generation (review). Phys. Solid State 60, 1471–1486 (2018).

    Article  ADS  Google Scholar 

  12. Chauleau, J.-Y., Haltz, E., Carrétéro, C., Fusil, S. & Viret, M. Multi-stimuli manipulation of antiferromagnetic domains assessed by second-harmonic imaging. Nat. Mater. 16, 803–807 (2017).

    Article  ADS  Google Scholar 

  13. Lin, K.-Q., Bange, S. & Lupton, J. M. Quantum interference in second-harmonic generation from monolayer WSe2. Nat. Phys. 15, 242–246 (2019).

    Article  Google Scholar 

  14. Cui, C., Xue, F., Hu, W.-J. & Li, L.-J. Two-dimensional materials with piezoelectric and ferroelectric functionalities. npj 2D Mater. Appl. 2, 1–14 (2018).

    Google Scholar 

  15. Schäber, H. & Gerken, R. Beiträge zur chemie der elemente niob und tantal. XXIX. NbOJ3 und NbOJ2. Darstellung, eigenschaften und thermisches verhalten. Z. Anorg. Allg. Chem. 317, 105–112 (1962).

    Article  Google Scholar 

  16. Rijnsdorp, J. & Jellinek, F. The crystal structure of niobium oxide diiodide NbOI2. J. Less-Common Met. 61, 79–82 (1978).

    Article  Google Scholar 

  17. Hillebrecht, H. et al. Structural and scanning microscopy studies of layered compounds MCl3 (M = Mo, Ru, Cr) and MOCl2 (M = V, Nb, Mo, Ru, Os). J. Alloys Compd. 246, 70–79 (1997).

    Article  Google Scholar 

  18. Beck, J. & Kusterer, C. Crystal structure of NbOBr2. Z. Anorg. Allg. Chem. 632, 2193–2194 (2006).

    Article  Google Scholar 

  19. Wu, Y. et al. Data-driven discovery of high performance layered van der Waals piezoelectric NbOI2. Nat. Commun. 13, 1884 (2022).

    Article  ADS  Google Scholar 

  20. Pugachev, A. et al. Broken local symmetry in paraelectric BaTiO3 proved by second harmonic generation. Phys. Rev. Lett. 108, 247601 (2012).

    Article  ADS  Google Scholar 

  21. Clark, D. et al. Near bandgap second-order nonlinear optical characteristics of MoS2 monolayer transferred on transparent substrates. Appl. Phys. Lett. 107, 131113 (2015).

    Article  ADS  Google Scholar 

  22. Woodward, R. et al. Characterization of the second-and third-order nonlinear optical susceptibilities of monolayer MoS2 using multiphoton microscopy. 2D Mater. 4, 011006 (2016).

    Article  Google Scholar 

  23. Säynätjoki, A. et al. Ultra-strong nonlinear optical processes and trigonal warping in MoS2 layers. Nat. Commun. 8, 1–8 (2017).

    Article  Google Scholar 

  24. Seyler, K. L. et al. Electrical control of second-harmonic generation in a WSe2 monolayer transistor. Nat. Nanotechnol. 10, 407 (2015).

    Article  ADS  Google Scholar 

  25. Karvonen, L. et al. Investigation of second- and third-harmonic generation in few-layer gallium selenide by multiphoton microscopy. Sci Rep. 5, 10334 (2015).

    Article  ADS  Google Scholar 

  26. Malard, L. M., Alencar, T. V., Barboza, A. P. M., Mak, K. F. & de Paula, A. M. Observation of intense second harmonic generation from MoS2 atomic crystals. Phys. Rev. B 87, 201401 (2013).

    Article  ADS  Google Scholar 

  27. Wu, L. et al. Giant anisotropic nonlinear optical response in transition metal monopnictide Weyl semimetals. Nat. Phys. 13, 350–355 (2017).

    Article  Google Scholar 

  28. Bergfeld, S. & Daum, W. Second-harmonic generation in GaAs: experiment versus theoretical predictions of \(\chi _{xyz}^{(2)}\). Phys. Rev. Lett. 90, 036801 (2003).

    Article  ADS  Google Scholar 

  29. Shoji, I., Kondo, T., Kitamoto, A., Shirane, M. & Ito, R. Absolute scale of second-order nonlinear-optical coefficients. JOSA B 14, 2268–2294 (1997).

    Article  ADS  Google Scholar 

  30. Yariv A. & Yeh P. Photonics: Optical Electronics in Modern Communications (Oxford Univ. Press, 2007).

  31. Shen, Y. R. The Principles of Nonlinear Optics (Wiley. 1984).

  32. Peierls R. E. Quantum Theory of Solids (Clarendon, 1996).

  33. Jia, Y., Zhao, M., Gou, G., Zeng, X. C. & Li, J. Niobium oxide dihalides NbOX2: a new family of two-dimensional van der Waals layered materials with intrinsic ferroelectricity and antiferroelectricity. Nanoscale Horiz. 4, 1113–1123 (2019).

    Article  ADS  Google Scholar 

  34. Hybertsen, M. S. & Louie, S. G. Electron correlation in semiconductors and insulators: band gaps and quasiparticle energies. Phys. Rev. B 34, 5390–5413 (1986).

    Article  ADS  Google Scholar 

  35. Hedin, L. New method for calculating the one-particle Green's function with application to the electron-gas problem. Phys. Rev. 139, A796–A823 (1965).

    Article  ADS  Google Scholar 

  36. Rouxel J. Crystal Chemistry and Properties of Materials with Quasi-One-Dimensional Structures: A Chemical and Physical Synthetic Approach (D. Reidel, 1986).

  37. Fang, Y., Wang, F., Wang, R., Zhai, T. & Huang, F. 2D NbOI2: a chiral semiconductor with highly in‐plane anisotropic electrical and optical properties. Adv. Mater. 33, 2101505 (2021).

    Article  Google Scholar 

  38. Bloembergen, N. & Pershan, P. S. Light waves at the boundary of nonlinear media. Phys. Rev. 128, 606–622 (1962).

    Article  ADS  MathSciNet  MATH  Google Scholar 

  39. Hopfield, J. J. & Thomas, D. G. Theoretical and experimental effects of spatial dispersion on the optical properties of crystals. Phys. Rev. 132, 563–572 (1963).

    Article  ADS  Google Scholar 

  40. Li, Y. et al. Probing symmetry properties of few-layer MoS2 and h-BN by optical second-harmonic generation. Nano Lett. 13, 3329 (2013).

    Article  ADS  Google Scholar 

  41. Song, Y. et al. Extraordinary second harmonic generation in ReS2 atomic crystals. ACS Photon. 5, 3485–3491 (2018).

    Article  Google Scholar 

  42. Vella, D., Bico, J., Boudaoud, A., Roman, B. & Reis, P. M. The macroscopic delamination of thin films from elastic substrates. Proc. Natl Acad. Sci. USA 106, 10901–10906 (2009).

    Article  ADS  Google Scholar 

  43. Fickler, R. et al. Quantum entanglement of high angular momenta. Science 338, 640–643 (2012).

    Article  ADS  Google Scholar 

  44. Fedrizzi, A., Herbst, T., Poppe, A., Jennewein, T. & Zeilinger, A. A wavelength-tunable fiber-coupled source of narrowband entangled photons. Opt. Express 15, 15377–15386 (2007).

    Article  ADS  Google Scholar 

  45. Zhang, G. et al. An integrated silicon photonic chip platform for continuous-variable quantum key distribution. Nat. Photon. 13, 839–842 (2019).

    Article  ADS  Google Scholar 

  46. Hickstein, D. D. et al. Self-organized nonlinear gratings for ultrafast nanophotonics. Nat. Photon. 13, 494–499 (2019).

    Article  ADS  Google Scholar 

  47. Tran, R. J., Sly, K. L. & Conboy, J. C. Applications of surface second harmonic generation in biological sensing. Ann. Rev. Anal. Chem. 10, 387–414 (2017).

    Article  Google Scholar 

  48. Miller, D. A. B. Are optical transistors the logical next step? Nat. Photon. 4, 3–5 (2010).

    Article  ADS  Google Scholar 

  49. Gallo, K. & Assanto, G. All-optical diode based on second-harmonic generation in an asymmetric waveguide. JOSA B 16, 267–269 (1999).

    Article  ADS  Google Scholar 

  50. Fejer, M. M., Magel, G. A., Jundt, D. H. & Byer, R. L. Quasi-phase-matched second harmonic generation: tuning and tolerances. IEEE J. Quantum Electron. 28, 2631–2654 (1992).

    Article  ADS  Google Scholar 

  51. Bruker APEX3 (Bruker Nano, Inc., 2019).

  52. Sheldrick, G. M. SHELXT–Integrated space-group and crystal-structure determination. Acta Crystallogr. A Found. Adv. 71, 3–8 (2015).

    Article  MATH  Google Scholar 

  53. Schubert M. Infrared Ellipsometry on Semiconductor Layer Structures: Phonons, Plasmons, and Polaritons Vol. 209 (Springer, 2004).

  54. Losurdo M. & Hingerl K. Ellipsometry at the Nanoscale (Springer, 2013).

  55. Schmidt, D. et al. Monoclinic optical constants, birefringence, and dichroism of slanted titanium nanocolumns determined by generalized ellipsometry. Appl. Phys. Lett. 94, 011914 (2009).

    Article  ADS  Google Scholar 

  56. Schmidt, D. et al. Generalized ellipsometry for monoclinic absorbing materials: determination of optical constants of Cr columnar thin films. Opt. Lett. 34, 992–994 (2009).

    Article  ADS  Google Scholar 

  57. Schubert, M. Polarization-dependent optical parameters of arbitrarily anisotropic homogeneous layered systems. Phys. Rev. B 53, 4265–4274 (1996).

    Article  ADS  Google Scholar 

  58. Giannozzi, P. et al. QUANTUM ESPRESSO: a modular and open-source software project for quantum simulations of materials. J. Phys. Condens. Matter 21, 395502 (2009).

    Article  Google Scholar 

  59. Giannozzi, P. et al. Advanced capabilities for materials modelling with Quantum ESPRESSO. J. Phys. Condens. Matter 29, 465901 (2017).

    Article  Google Scholar 

  60. Hamann, D. R. Optimized norm-conserving Vanderbilt pseudopotentials. Phys. Rev. B 88, 085117 (2013).

    Article  ADS  Google Scholar 

  61. Perdew, J. P., Burke, K. & Ernzerhof, M. Generalized gradient approximation made simple. Phys. Rev. Lett. 77, 3865–3868 (1996).

    Article  ADS  Google Scholar 

  62. Grimme, S. Semiempirical GGA-type density functional constructed with a long-range dispersion correction. J. Comput. Chem. 27, 1787–1799 (2006).

    Article  Google Scholar 

  63. Monkhorst, H. J. & Pack, J. D. Special points for Brillouin-zone integrations. Phys. Rev. B 13, 5188–5192 (1976).

    Article  ADS  MathSciNet  Google Scholar 

  64. Rohlfing, M. & Louie, S. G. Electron-hole excitations and optical spectra from first principles. Phys. Rev.B 62, 4927–4944 (2000).

    Article  ADS  Google Scholar 

  65. Deslippe, J. et al. BerkeleyGW: a massively parallel computer package for the calculation of the quasiparticle and optical properties of materials and nanostructures. Comput. Phys. Commun. 183, 1269–1289 (2012).

    Article  ADS  Google Scholar 

  66. Ismail-Beigi, S. Truncation of periodic image interactions for confined systems. Phys. Rev. B 73, 233103 (2006).

    Article  ADS  Google Scholar 

  67. da Jornada, F. H., Qiu, D. Y. & Louie, S. G. Nonuniform sampling schemes of the Brillouin zone for many-electron perturbation-theory calculations in reduced dimensionality. Phys. Rev. B 95, 035109 (2017).

    Article  ADS  Google Scholar 

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Acknowledgements

I.A. acknowledges funding support through a Humboldt Research Fellowship from the Alexander von Humboldt Foundation. K.P.L. acknowledges support from the Singapore National Research Foundation (NRF), Competitive Research Program NRF-CRP22-2019-0006, Prime Minister’s Office, Singapore. T.C.S. acknowledges support from the Ministry of Education (MOE), Singapore, under AcRF Tier 2 grant (MOE2019-T2-1-006). G.E. acknowledges support from MOE, Singapore, under AcRF Tier 3 grant (MOE2018-T3-1-005) and the Singapore NRF for funding the research under medium-sized centre programme. The authors would like to acknowledge the Singapore Synchrotron Light Source (SSLS) for providing the facility necessary for conducting the Mueller matrix ellipsometry measurements. S.A.M. acknowledges LMUexcellent, the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy—EXC 2089/1—390776260, the EPSRC Reactive Plasmonics Programme EP/M013812/1, and the Lee Lucas Chair in Physics.

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Authors and Affiliations

  1. Department of Chemistry, National University of Singapore, Singapore, Singapore

    Ibrahim Abdelwahab, Menglong Zhu & Kian Ping Loh

  2. Chair in Hybrid Nanosystems, Nanoinstitute Munich, Faculty of Physics, Ludwig-Maxilimians-Universität München, Munich, Germany

    Ibrahim Abdelwahab, Benjamin Tilmann, Rodrigo Berté, Leonardo de S. Menezes & Stefan A. Maier

  3. Department of Physics, National University of Singapore, Singapore, Singapore

    Yaze Wu, Ivan Verzhbitskiy, Goki Eda & Su Ying Quek

  4. Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, Singapore, Singapore

    Yaze Wu, Ivan Verzhbitskiy, Fengyuan Xuan, Goki Eda, Su Ying Quek & Kian Ping Loh

  5. School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore

    David Giovanni & Tze Chien Sum

  6. Instituto de Física, Universidade Federal de Goiás, Goiania, Brazil

    Rodrigo Berté

  7. Departamento de Física, Universidade Federal de Pernambuco, Recife, Brazil

    Leonardo de S. Menezes

  8. NUS Graduate School, Integrative Sciences and Engineering Programme, National University of Singapore, Singapore, Singapore

    Su Ying Quek

  9. Department of Materials Science and Engineering, National University of Singapore, Singapore, Singapore

    Su Ying Quek

  10. School of Physics and Astronomy, Monash University, Melbourne, Victoria, Australia

    Stefan A. Maier

  11. Department of Physics, Imperial College London, London, UK

    Stefan A. Maier

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  1. Ibrahim Abdelwahab
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Contributions

I.A., S.A.M. and K.P.L. conceived the project and designed the experiments. I.A. performed micromechanical cleavage, two-dimensional dry transfer, device fabrication and material characterization under the supervision of S.A.M. and K.P.L. I.A., B.T., D.G. and R.B. performed all the optical characterizations under the guidance of L.d.S.M., T.C.S., S.A.M., and K.P.L. Y.W. and F.X. performed the calculations and theoretical analysis under supervision of S.Y.Q. I.V. synthesized the NbOI2 bulk crystals under the supervision of G.E. M.Z. performed the ARPES measurements. I.A. wrote the manuscript with input from all authors.

Corresponding authors

Correspondence to Stefan A. Maier or Kian Ping Loh.

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Supplementary information

Supplementary Information

Supplementary Tables S1–S3, Supplementary Figures S1–S16, Supplementary Note S1-S7

Supplementary Video 1

Polarization-dependent transmission measurements of NbOI2 nanosheet

Supplementary Data 1

Crystallographic Information File of NbOI2 at 298 K

Supplementary Data 2

Crystallographic Information File of NbOI2 at 100 K

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Abdelwahab, I., Tilmann, B., Wu, Y. et al. Giant second-harmonic generation in ferroelectric NbOI2. Nat. Photon. 16, 644–650 (2022). https://doi.org/10.1038/s41566-022-01021-y

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