Two-dimensional semiconductors have emerged as a new class of materials for nanophotonics owing to their strong exciton–photon interaction1,2 and their ability to be engineered and integrated into devices3. Here we take advantage of these properties to engineer an efficient lasing medium based on direct-bandgap interlayer excitons in rotationally aligned atomically thin heterostructures4. Lasing is measured from a transition-metal dichalcogenide heterobilayer (WSe2–MoSe2) integrated in a silicon nitride grating resonator. An abrupt increase in the spatial coherence of the emission is observed across the lasing threshold. The work establishes interlayer excitons in two-dimensional heterostructures as a gain medium with spatially coherent lasing emission and potential for heterogeneous integration. With electrically tunable exciton–photon interaction strengths5 and long-range dipolar interactions, these interlayer excitons are promising for application as low-power, ultrafast lasers and modulators and for the study of many-body quantum phenomena6.
Subscribe to Journal
Get full journal access for 1 year
only $3.90 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Tax calculation will be finalised during checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
Data that support the findings of this study are available from the corresponding author on reasonable request.
Mak, K. F., Lee, C., Hone, J., Shan, J. & Heinz, T. F. Atomically thin MoS2: a new direct-gap semiconductor. Phys. Rev. Lett. 105, 136805 (2010).
Splendiani, A. et al. Emerging photoluminescence in monolayer MoS2. Nano Lett. 10, 1271–1275 (2010).
Geim, A. K. & Grigorieva, I. V. Van der Waals heterostructures. Nature 499, 419–425 (2013).
Zhang, C. et al. Interlayer couplings, moiré patterns, and 2D electronic superlattices in MoS2/WSe2 hetero-bilayers. Sci. Adv. 3, e1601459 (2017).
Fang, H. et al. Strong interlayer coupling in van der Waals heterostructures built from single-layer chalcogenides. Proc. Natl Acad. Sci. USA 111, 6198–6202 (2014).
Fogler, M. M., Butov, L. V. & Novoselov, K. S. High-temperature superfluidity with indirect excitons in van der Waals heterostructures. Nat. Commun. 5, 4555 (2014).
Eaton, S. W., Fu, A., Wong, A. B., Ning, C. Z. & Yang, P. Semiconductor nanowire lasers. Nat. Rev. Mater. 1, 16028 (2016).
Noginov, M. A. et al. Demonstration of a spaser-based nanolaser. Nature 460, 1110–1112 (2009).
Noda, S. Seeking the ultimate nanolaser. Science 314, 260–261 (2006).
Wu, S. et al. Monolayer semiconductor nanocavity lasers with ultralow thresholds. Nature 520, 69–72 (2015).
Ye, Y. et al. Monolayer excitonic laser. Nat. Photon. 9, 733–737 (2015).
Salehzadeh, O., Djavid, M., Tran, N. H., Shih, I. & Mi, Z. Optically pumped two-dimensional MoS2 lasers operating at room-temperature. Nano Lett. 15, 5302–5306 (2015).
Li, Y. et al. Room-temperature continuous-wave lasing from monolayer molybdenum ditelluride integrated with a silicon nanobeam cavity. Nat. Nanotechnol. 12, 987–992 (2017).
Shang, J. et al. Room-temperature 2D semiconductor activated vertical-cavity surface-emitting lasers. Nat. Commun. 8, 543 (2017).
Zhao, L. et al. High-temperature continuous-wave pumped lasing from large-area monolayer semiconductors grown by chemical vapor deposition. ACS Nano 12, 9390–9396 (2018).
Reeves, L., Wang, Y. & Krauss, T. F. 2D material microcavity light emitters: to lase or not to lase? Adv. Opt. Mater. 6, 1800272 (2018).
Butov, L. V., Zrenner, A., Abstreiter, G., Böhm, G. & Weimann, G. Condensation of indirect excitons in coupled AlAs/GaAs quantum wells. Phys. Rev. Lett. 73, 304–307 (1994).
Rigosi, A. F., Hill, H. M., Li, Y., Chernikov, A. & Heinz, T. F. Probing interlayer interactions in transition metal dichalcogenide heterostructures by optical spectroscopy: MoS2/WS2 and MoSe2/WSe2. Nano Lett. 15, 5033–5038 (2015).
Zhang, L. et al. Highly valley-polarized singlet and triplet interlayer excitons in van der Waals heterostructure. Phys. Rev. B 100, 041402 (2019).
Lee, C. H. et al. Atomically thin p-n junctions with van der Waals heterointerfaces. Nat. Nanotechnol. 9, 676–681 (2014).
Ross, J. S. et al. Interlayer exciton optoelectronics in a 2D heterostructure p-n junction. Nano Lett. 17, 638–643 (2017).
Zhang, L., Gogna, R., Burg, W., Tutuc, E. & Deng, H. Photonic-crystal exciton-polaritons in monolayer semiconductors. Nat. Commun. 9, 713 (2018).
Spivak, B. & Luryi, S. in Future Trends in Microelectronics (eds Spivak, B., Luryi, S. & Zaslavsky, A.) 68–76 (Wiley-Blackwell, 2007).
Deng, H., Solomon, G. S., Hey, R., Ploog, K. H. & Yamamoto, Y. Spatial coherence of a polariton condensate. Phys. Rev. Lett. 99, 126403 (2007).
Hoang, T. B., Akselrod, G. M., Yang, A., Odom, T. W. & Mikkelsen, M. H. Millimeter-scale spatial coherence from a plasmon laser. Nano Lett. 17, 6690–6695 (2017).
Daskalakis, K. S., Maier, S. A. & Kéna-Cohen, S. Spatial coherence and stability in a disordered organic polariton condensate. Phys. Rev. Lett. 115, 035301 (2015).
Yu, H., Liu, G.-B., Tang, J., Xu, X. & Yao, W. Moiré excitons: from programmable quantum emitter arrays to spin-orbit–coupled artificial lattices. Sci. Adv. 3, e1701696 (2017).
Wu, F., Lovorn, T. & MacDonald, A. H. Theory of optical absorption by interlayer excitons in transition metal dichalcogenide heterobilayers. Phys. Rev. B 97, 035306 (2018).
Tran, K. et al. Evidence for moiré excitons in van der Waals heterostructures. Nature 567, 71–75 (2019).
Seyler, K. L. et al. Signatures of moiré-trapped valley excitons in MoSe2/WSe2 heterobilayers. Nature 567, 66–70 (2019).
Jin, C. et al. Observation of moiré excitons in WSe2/WS2 heterostructure superlattices. Nature 567, 76–80 (2019); correction 569, E7 (2019).
Kirstaedter, N. et al. Low threshold, large To injection laser emission from (InGa)As quantum dots. Electron. Lett. 30, 1416–1417 (1994).
Shahnazaryan, V., Kyriienko, O. & Shelykh, I. A. Adiabatic preparation of a cold exciton condensate. Phys. Rev. B 91, 085302 (2015).
Jin, Z., Li, X., Mullen, J. T. & Kim, K. W. Intrinsic transport properties of electrons and holes in monolayer transition-metal dichalcogenides. Phys. Rev. B 90, 045422 (2014).
We acknowledge support from the Army Research Office under awards W911NF-17-1-0312. H.D. acknowledges support from the Asian Office of Aerospace R&D under awards FA2386-18-1-4086. E.T. acknowledges support from Intel Corp., and the Welch Foundation grant F-2018-20190330.
The authors declare no competing interests.
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Extended data figures and tables
a, b, Optical image (a) and angle-resolved SHG measurements (b; open circles) of WSe2/MoSe2 heterobilayers. c, d, As a, b but for a different sample. The field of view of the optical images is around 60 μm. Solid lines in b, d, are fits by a cos2(3θ) function, which give relative twist angles of 0.22°± 1.78° for b, and 0.34° ± 1.5° for d.
a, Time-resolved PL spectrum for TM emission. b, Line-cut of a near 1.38 eV. Red line is a bi-exponential fit to the data, with a fitted lifetime of 2 ns.
The normalized intensity of PL from the device is shown as a function of position. Spectral filters centred around their respective exciton peak energies were applied for each image. The white contours mark the regions of heterobilayer (a), MoSe2 (b) and WSe2 (c).
Shown are simulated normalized electric field profiles as a function of position near the centre of a grating cavity with lateral dimensions of 100 μm × 100 μm. a, TE-polarized light at the cavity resonance at k = 0, showing strong field enhancement in the grating layer including at its surface where the heterobilayer is placed. b, TM-polarized light at the same wavelength as a, showing negligible cavity effects. White lines outline different layers of the grating cavity. The corresponding enhancement of the exciton radiative decay rate, or the Purcell factor, is calculated to be around 2.4.
The photon occupancy (red) and linewidth (blue) of TE emission from the heterobilayer versus input pump power, similar to that shown in Fig. 3b of the main text but measured on a different day to show the reproducibility of the device. The error bars on the photon occupancy data include the shot noise and detector read noise. The error bars on the linewidth data correspond to the 95% confidence interval of the Lorentzian fit.
The log–log plot of photon occupancy versus pump power. The diamonds represent measured data shown in Fig. 3b of the main text, and the solid line is a rate-equation fitting. Details of the rate equation simulation are described in Methods.
Temperature-dependent real space PL spectra of the sample studied in the main text.
Schematic diagram of the optical experimental setup as described in Methods. BS, beam splitter; LP, long-pass filter; BP, band-pass filter; CCD, charge-coupled device.
Shown are temporal coherence interference fringes at g(1)(τ = 0) measured using a two-retro-reflector Michelson interferometer under CW excitation above threshold. a, Interferogram image at τ = 0. b, Horizontal line-cut of a around y = 1.5 μm. The red line is a fit to the Gaussian pump beam profile modulated by a cosine function. Here g(1)(τ = 0) = 0.78.
About this article
Cite this article
Paik, E.Y., Zhang, L., Burg, G.W. et al. Interlayer exciton laser of extended spatial coherence in atomically thin heterostructures. Nature 576, 80–84 (2019). https://doi.org/10.1038/s41586-019-1779-x
Silica optical fiber integrated with two-dimensional materials: towards opto-electro-mechanical technology
Light: Science & Applications (2021)
Light: Science & Applications (2021)
Nature Reviews Physics (2021)
Strong exciton-photon interaction and lasing of two-dimensional transition metal dichalcogenide semiconductors
Nano Research (2021)
p-/n-Type modulation of 2D transition metal dichalcogenides for electronic and optoelectronic devices
Nano Research (2021)