Abstract

Quantum dots embedded within nanowires represent one of the most promising technologies for applications in quantum photonics. Whereas the top-down fabrication of such structures remains a technological challenge, their bottom-up fabrication through self-assembly is a potentially more powerful strategy. However, present approaches often yield quantum dots with large optical linewidths, making reproducibility of their physical properties difficult. We present a versatile quantum-dot-in-nanowire system that reproducibly self-assembles in core–shell GaAs/AlGaAs nanowires. The quantum dots form at the apex of a GaAs/AlGaAs interface, are highly stable, and can be positioned with nanometre precision relative to the nanowire centre. Unusually, their emission is blue-shifted relative to the lowest energy continuum states of the GaAs core. Large-scale electronic structure calculations show that the origin of the optical transitions lies in quantum confinement due to Al-rich barriers. By emitting in the red and self-assembling on silicon substrates, these quantum dots could therefore become building blocks for solid-state lighting devices and third-generation solar cells.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

References

  1. 1.

    Semiconductor quantum light sources. Nature Photon. 1, 215–223 (2007).

  2. 2.

    , , & Optically bright quantum dots in single nanowires. Nano Lett. 5, 1439–1443 (2005).

  3. 3.

    et al. A highly efficient single-photon source based on a quantum dot in a photonic nanowire. Nature Photon. 4, 174–177 (2010).

  4. 4.

    et al. Spontaneous emission control of single quantum dots in bottom-up nanowire waveguides. Appl. Phys. Lett. 100, 121106 (2012).

  5. 5.

    et al. Bright single-photon sources in bottom-up tailored nanowires. Nature Commun. 3, 737 (2012).

  6. 6.

    et al. Single photon emission from positioned GaAs/AlGaAs photonic nanowires. Appl. Phys. Lett. 96, 211117 (2010).

  7. 7.

    , , & InAs quantum dot arrays decorating the facets of GaAs nanowires. ACS Nano 4, 5985–5993 (2010).

  8. 8.

    et al. Ultrafast room temperature single-photon source from nanowire-quantum dots. Nano Lett. 12, 2977–2981 (2012).

  9. 9.

    & Semiconductor nanowires: Optics and optoelectronics. Appl. Phys. A 85, 209–215 (2006).

  10. 10.

    et al. Enhanced absorption and carrier collection in Si wire arrays for photovoltaic applications. Nature Mater. 9, 239–244 (2010).

  11. 11.

    et al. Single-mode solid-state single photon source based on isolated quantum dots in pillar microcavities. Appl. Phys. Lett. 79, 2865–2867 (2001).

  12. 12.

    , , , & Carrier transport in self-organized InAs/GaAs quantum-dot structures studied by single-dot spectroscopy. Phys. Rev. B 73, 155336 (2006).

  13. 13.

    et al. Hole recapture limited single photon generation from a single n-type charge-tunable quantum dot. Appl. Phys. Lett. 92, 193103 (2008).

  14. 14.

    , , , & Ga-assisted catalyst-free growth mechanism of GaAs nanowires by molecular beam epitaxy. Phys. Rev. B 77, 155326 (2008).

  15. 15.

    et al. Long range epitaxial growth of prismatic heterostructures on the facets of catalyst-free GaAs nanowires. J. Mater. Chem. 19, 840–848 (2009).

  16. 16.

    et al. Prismatic quantum heterostructures synthesized on molecular-beam epitaxy GaAs nanowires. Small 4, 899–903 (2008).

  17. 17.

    & Mechanisms of self-ordering of quantum nanostructures grown on nonplanar surfaces. Phys. Rev. Lett. 81, 2962–2965 (1998).

  18. 18.

    , , & Mechanisms of self-ordering in nonplanar epitaxy of semiconductor nanostructures. Phys. Rev. B 65, 205306 (2002).

  19. 19.

    et al. Nanometer-scale sharpness in corner-overgrown heterostructures. Appl. Phys. Lett. 93, 193117 (2008).

  20. 20.

    et al. Phase segregation in AlInP shells on GaAs nanowires. Nano Lett. 6, 2743–2747 (2006).

  21. 21.

    et al. Coulomb interactions in single charged self-assembled quantum dots: Radiative lifetime and recombination energy. Phys. Rev. B 77, 245311 (2008).

  22. 22.

    & Linear combination of bulk bands method for large-scale electronic structure calculations on strained nanostructures. Phys. Rev. B 59, 15806–15818 (1999).

  23. 23.

    , , & Many-body pseudopotential theory of excitons in InP and CdSe quantum dots. Phys. Rev. B 60, 1819–1829 (1999).

  24. 24.

    , , & Gallium arsenide p-i-n radial structures for photovoltaic applications. Appl. Phys. Lett. 94, 173108 (2009).

  25. 25.

    et al. Few-electron quantum dots in nanowires. Nano Lett. 4, 1621–1625 (2004).

  26. 26.

    , & Nanoscale avalanche photodiodes for highly sensitive and spatially resolved photon detection. Nature Mater. 5, 352–356 (2006).

  27. 27.

    et al. Selective excitation and detection of spin states in a single nanowire quantum dot. Nano Lett. 9, 1989–1993 (2009).

  28. 28.

    et al. Measurement of the g-factor tensor in a quantum dot and disentanglement of exciton spins. Phys. Rev. B 84, 195305 (2011).

  29. 29.

    et al. The interpretation of HREM images of supported metal catalysts using image simulation: profile view images. Ultramicroscopy 72, 135–164 (1998).

  30. 30.

    et al. Optimization of tin dioxide nanosticks faceting for the improvement of palladium nanocluster epitaxy. Appl. Phys. Lett. 80, 329–331 (2002).

  31. 31.

    et al. Catalyst-free nanowires with axial InxGa1−xAs/GaAs heterostructures. Nanotechnology 20, 075603 (2009).

  32. 32.

    , & Atomistic pseudopotential calculations of thickness-fluctuation GaAs quantum dots. Phys. Rev. B 79, 125329 (2009).

  33. 33.

    & Solving Schrodinger’s equation around a desired energy—Application to silicon quantum dots. J. Chem. Phys. 100, 2394–2397 (1994).

  34. 34.

    & O(N) methods in electronic structure calculations. Rep. Prog. Phys. 75, 036503 (2012).

  35. 35.

    , , & Introducing ONETEP: Linear-scaling density functional simulations on parallel computers. J. Chem. Phys. 122, 084119 (2005).

  36. 36.

    , , & Linear-scaling density-functional simulations of charged point defects in Al2O3 using hierarchical sparse matrix algebra. J. Chem. Phys. 133, 114111 (2010).

  37. 37.

    , , , & Linear-scaling density-functional theory with tens of thousands of atoms: Expanding the scope and scale of calculations with ONETEP. Comput. Phys. Commun. 180, 1041–1053 (2009).

  38. 38.

    , , & Fermi-level pinning can determine polarity in semiconductor nanorods. Phys. Rev. B 85, 115404 (2012).

  39. 39.

    , & Generalized Wannier functions: A comparison of molecular electric dipole polarizabilities. Phys. Rev. B 85, 193101 (2012).

  40. 40.

    & Self-interaction correction to density-functional approximations for many-electron systems. Phys. Rev. B 23, 5048–5079 (1981).

  41. 41.

    & VESTA 3 for three-dimensional visualization of crystal, volumetric and morphology data. J. Appl. Crystallogr. 44, 1272–1276 (2011).

Download references

Acknowledgements

A.F.i.M. acknowledges funding from ERC through the UpCon grant and SNF through Grant No. 134506. Both A.F.i.M. and R.J.W. acknowledge support from NCCR QSIT. The Phantoms Foundation is acknowledged for sponsoring B.K.’s visit to Lund University. This work was supported by the Spanish MICINN Projects MAT2010-15138, CSD2009-00013 and CSD2009-00050. J.A. and J.R.M. acknowledge Generalitat de Catalunya 2009-SGR-770, NanoAraCat and XaRMAE and European RDF support. The authors acknowledge F. J. Belarre for the making of the TEM cross-sections; A.G. thanks L. Samuelson and the Swedish Research Council for support. D.D.O. acknowledges N. D. M. Hine and the ONETEP developers’ group for discussions and software support, and the EPFL HPC service for generous provision of computing resources. The work carried out by J.W.L. and A.Z. was funded by the US Department of Energy, Office of Science, Basic Energy Science, Materials Sciences and Engineering under contract number DE-AC36-08GO28308 to NREL and CU Boulder.

Author information

Author notes

    • M. Heiss

    These authors contributed equally to this work

Affiliations

  1. Laboratoire des Matériaux Semiconducteurs, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland

    • M. Heiss
    • , Y. Fontana
    • , B. Ketterer
    • , S. Conesa-Boj
    • , E. Russo-Averchi
    •  & A. Fontcuberta i Morral
  2. Solid State Physics, The Nanometer Consortium, Lund University, Box 118, Lund S-221 00, Sweden

    • A. Gustafsson
  3. Department of Physics, University of Basel, Klingelbergstrasse 82, CH4056 Basel, Switzerland

    • G. Wüst
    • , A. V. Kuhlmann
    • , J. Houel
    •  & R. J. Warburton
  4. Instituto de Nanociencia de Aragon-ARAID and Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50018 Zaragoza, Spain

    • C. Magen
  5. Theory and Simulation of Materials (THEOS), École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland

    • D. D. O’Regan
    •  & N. Marzari
  6. National Renewable Energy Laboratory, Golden, Colorado 80401, USA

    • J. W. Luo
  7. Catalonia Institute for Energy Research, IREC. 08930 Sant Adrià del Besòs, Spain

    • J. R. Morante
  8. Department dÉlectrònica, Universitat de Barcelona, 08028 Barcelona, Spain

    • J. R. Morante
  9. Interdisciplinary Center for Electron Microscopy, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland

    • M. Cantoni
  10. Institució Catalana de Recerca i Estudis Avançats (ICREA) and Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, E-08193 Bellaterra, CAT, Spain

    • J. Arbiol
  11. University of Colorado, Boulder, Colorado 80309, USA

    • A. Zunger

Authors

  1. Search for M. Heiss in:

  2. Search for Y. Fontana in:

  3. Search for A. Gustafsson in:

  4. Search for G. Wüst in:

  5. Search for C. Magen in:

  6. Search for D. D. O’Regan in:

  7. Search for J. W. Luo in:

  8. Search for B. Ketterer in:

  9. Search for S. Conesa-Boj in:

  10. Search for A. V. Kuhlmann in:

  11. Search for J. Houel in:

  12. Search for E. Russo-Averchi in:

  13. Search for J. R. Morante in:

  14. Search for M. Cantoni in:

  15. Search for N. Marzari in:

  16. Search for J. Arbiol in:

  17. Search for A. Zunger in:

  18. Search for R. J. Warburton in:

  19. Search for A. Fontcuberta i Morral in:

Contributions

M.H., E.R-A. and A.F.i.M. grew the samples. J.A., J.R.M. and C.M. performed HAADF STEM and EELS analysis. S.C-B. and M.C. mapped the composition of the quantum dots by EDX. J.A. and S.C-B. worked on the atomic modelling of the quantum dots. A.G. and B.K. measured the cathodoluminescence. M.H., Y.F., G.W., A.V.K., J.H. and R.J.W. participated in the optical spectroscopy studies. D.D.O. and N.M. performed density functional theory calculations. J.W.L. and A.Z. performed the empirical pseudopotential calculations. A.F.i.M. conceived and designed the experiments, and together with R.J.W., A.Z. and N.M. supervised the project. Y.F. made the figures and artwork. A.F.i.M., R.J.W., Y.F., A.Z., D.D.O., N.M. and J.A. wrote and edited the manuscript. All authors discussed the results and commented on the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding authors

Correspondence to M. Heiss or Y. Fontana or A. Fontcuberta i Morral.

Supplementary information

PDF files

  1. 1.

    Supplementary Information

    Supplementary Information

About this article

Publication history

Received

Accepted

Published

DOI

https://doi.org/10.1038/nmat3557

Further reading