Letter | Published:

Lasing in direct-bandgap GeSn alloy grown on Si

Nature Photonics 9, 88–92 (2015) | Download Citation

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Abstract

Large-scale optoelectronics integration is limited by the inability of Si to emit light efficiently1, because Si and the chemically well-matched Ge are indirect-bandgap semiconductors. To overcome this drawback, several routes have been pursued, such as the all-optical Si Raman laser2 and the heterogeneous integration of direct-bandgap III–V lasers on Si3,4,5,6,7. Here, we report lasing in a direct-bandgap group IV system created by alloying Ge with Sn8 without mechanically introducing strain9,10. Strong enhancement of photoluminescence emerging from the direct transition with decreasing temperature is the signature of a fundamental direct-bandgap semiconductor. For T ≤ 90 K, the observation of a threshold in emitted intensity with increasing incident optical power, together with strong linewidth narrowing and a consistent longitudinal cavity mode pattern, highlight unambiguous laser action11. Direct-bandgap group IV materials may thus represent a pathway towards the monolithic integration of Si-photonic circuitry and complementary metal–oxide–semiconductor (CMOS) technology.

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Acknowledgements

The authors acknowledge the hospitality of the IR beamline of the SLS, where the photoluminescence experiments were performed. Part of this work was funded by the Swiss National Science Foundation (SNF). This research received funding for CVD growth investigations from the European Community's Seventh Framework Programme (grant agreement no. 619509; project E2SWITCH) and the BMBF project UltraLowPow (16ES0060 K).

Author information

    • S. Wirths
    •  & R. Geiger

    These authors contributed equally to this work

Affiliations

  1. Peter Grünberg Institute 9 (PGI 9) and JARA-Fundamentals of Future Information Technologies, Forschungszentrum Juelich, 52425 Juelich, Germany

    • S. Wirths
    • , N. von den Driesch
    • , G. Mussler
    • , T. Stoica
    • , S. Mantl
    • , D. Buca
    •  & D. Grützmacher

  2. Laboratory for Micro- and Nanotechnology (LMN), Paul Scherrer Institut, CH-5232 Villigen, Switzerland

    • R. Geiger
    •  & H. Sigg

  3. Institute for Quantum Electronics, ETH Zürich, CH-8093 Zürich, Switzerland

    • R. Geiger
    •  & J. Faist

  4. Institute of Microwaves and Photonics, School of Electronic and Electrical Engineering, University of Leeds, Leeds LS2 9JT, UK

    • Z. Ikonic

  5. Peter Grünberg Institute 5 (PGI 5) and Ernst Ruska-Centrum, Forschungszentrum Juelich, 52425 Juelich, Germany

    • M. Luysberg

  6. Dpto. Física Aplicada, E.E.Industrial, Univ. de Vigo, Campus Universitario, 36310 Vigo, Spain

    • S. Chiussi

  7. University of Grenoble Alpes, F-38000 Grenoble, France

    • J. M. Hartmann

  8. CEA, LETI, MINATEC Campus, F-38054 Grenoble, France

    • J. M. Hartmann

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Contributions

J.M.H. fabricated the Ge/Si substrates. S.W. and D.B. planned the GeSn epitaxial growth experiments and S.W. and N.v.d.D. fabricated the GeSn/Ge/Si samples. M.L. and S.C. carried out the TEM measurements and analysis. S.W., D.B., G.M., N.v.d.D. and T.S. carried out crystal structure analysis including strain determination via XRD and RBS. Z.I. performed the bandstructure simulations. S.W. and R.G. performed the optical measurements. R.G. and H.S. performed the JDOS modelling, gain analysis and mode simulations. R.G. processed the GeSn cavities. S.M., J.F., D.B., H.S. and D.G. supervised the experiments and coordinated data interpretation. S.W., H.S., R.G. and D.B. wrote the paper. All authors discussed the results and commented on the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding authors

Correspondence to S. Wirths or D. Buca.

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DOI

https://doi.org/10.1038/nphoton.2014.321

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