Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Towards zero-threshold optical gain using charged semiconductor quantum dots

Nature Nanotechnology volume 12, pages 1140–1147 (2017)Cite this article

Subjects

Abstract

Colloidal semiconductor quantum dots are attractive materials for the realization of solution-processable lasers. However, their applications as optical-gain media are complicated by a non-unity degeneracy of band-edge states, because of which multiexcitons are required to achieve the lasing regime. This increases the lasing thresholds and leads to very short optical gain lifetimes limited by nonradiative Auger recombination. Here, we show that these problems can be at least partially resolved by employing not neutral but negatively charged quantum dots. By applying photodoping to specially engineered quantum dots with impeded Auger decay, we demonstrate a considerable reduction of the optical gain threshold due to suppression of ground-state absorption by pre-existing carriers. Moreover, by injecting approximately one electron per dot on average, we achieve a more than twofold reduction in the amplified spontaneous emission threshold, bringing it to the sub-single-exciton level. These measurements indicate the feasibility of ‘zero-threshold’ gain achievable by completely blocking the band-edge state with two electrons.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Concept of zero-threshold optical gain.
Figure 2: ‘Interface-engineered’ core/alloy/shell (C/A/S) CdSe/CdSexS1−x/CdS QDs.
Figure 3: Absorption spectra and PL dynamics of charged CdSe/CdSexS1−x/CdS C/A/S QDs.
Figure 4: Optical gain in charged CdSe/CdSexS1−x/CdS C/A/S QDs.
Figure 5: ASE and lasing thresholds in charged QDs.

Similar content being viewed by others

References

  1. Klimov, V. I. et al. Optical gain and stimulated emission in nanocrystal quantum dots. Science 290, 314–317 (2000).

    Article  CAS  Google Scholar 

  2. Nurmikko, A. What future for quantum dot-based light emitters? Nat. Nanotech. 10, 1001–1004 (2015).

    Article  CAS  Google Scholar 

  3. Pietryga, J. M. et al. Spectroscopic and device aspects of nanocrystal quantum dots. Chem. Rev. 116, 10513–10622 (2016).

    Article  CAS  Google Scholar 

  4. Asada, M., Miyamoto, Y. & Suematsu, Y. Gain and the threshold of 3-dimensional quantum-box lasers. IEEE J. Quantum Electron. 22, 1915–1921 (1986).

    Article  Google Scholar 

  5. Eisler, H.-J. et al. Color-selective semiconductor nanocrystal laser. Appl. Phys. Lett. 80, 4614–4616 (2002).

    Article  CAS  Google Scholar 

  6. Malko, A. V. et al. From amplified spontaneous emission to microring lasing using nanocrystal quantum dot solids. Appl. Phys. Lett. 81, 1303–1305 (2002).

    Article  CAS  Google Scholar 

  7. Schaller, R., Petruska, M. & Klimov, V. Tunable near-infrared optical gain and amplified spontaneous emission using PbSe nanocrystals. J. Phys. Chem. B 107, 13765–13768 (2003).

    Article  CAS  Google Scholar 

  8. Petruska, M. A., Malko, A. V., Voyles, P. M. & Klimov, V. I. High-performance, quantum dot nanocomposites for nonlinear optical and optical gain applications. Adv. Mater. 15, 610–613 (2003).

    Article  CAS  Google Scholar 

  9. Sundar, V. C., Eisler, H. J. & Bawendi, M. G. Room-temperature, tunable gain media from novel II–VI nanocrystal–titania composite matrices. Adv. Mater. 14, 739–743 (2002).

    Article  CAS  Google Scholar 

  10. Fan, F. et al. Continuous-wave lasing in colloidal quantum dot solids enabled by facet-selective epitaxy. Nature 544, 75–79 (2017).

    Article  CAS  Google Scholar 

  11. Klimov, V. I. et al. Quantization of multiparticle Auger rates in semiconductor quantum dots. Science 287, 1011–1013 (2000).

    Article  CAS  Google Scholar 

  12. Saba, M. et al. Exciton–exciton interaction and optical gain in colloidal CdSe/CdS dot/rod nanocrystals. Adv. Mater. 21, 4942–4946 (2009).

    Article  CAS  Google Scholar 

  13. Garcia-Santamaria, F. et al. Suppressed Auger recombination in ‘giant’ nanocrystals boosts optical gain performance. Nano Lett. 9, 3482–3488 (2009).

    Article  CAS  Google Scholar 

  14. Liao, Y. et al. Low threshold, amplified spontaneous emission from core-seeded semiconductor nanotetrapods incorporated into a sol–gel matrix. Adv. Mater. 24, OP159–OP164 (2012).

    CAS  Google Scholar 

  15. She, C. et al. Low-threshold stimulated emission using colloidal quantum wells. Nano Lett. 14, 2772–2777 (2014).

    Article  CAS  Google Scholar 

  16. Grim, J. Q. et al. Continuous-wave biexciton lasing at room temperature using solution-processed quantum wells. Nat. Nanotech. 9, 891–895 (2014).

    Article  CAS  Google Scholar 

  17. Yakunin, S. et al. Low-threshold amplified spontaneous emission and lasing from colloidal nanocrystals of caesium lead halide perovskites. Nat. Commun. 6, 8056 (2015).

    Article  CAS  Google Scholar 

  18. Zhu, H. et al. Lead halide perovskite nanowire lasers with low lasing thresholds and high quality factors. Nat. Mater. 14, 636–642 (2015).

    Article  CAS  Google Scholar 

  19. Sutherland, B. R. & Sargent, E. H. Perovskite photonic sources. Nat. Photon. 10, 295–302 (2016).

    Article  CAS  Google Scholar 

  20. Park, Y.-S. et al. Effect of the core/shell interface on Auger recombination evaluated by single-quantum-dot spectroscopy. Nano Lett. 14, 396–402 (2014).

    Article  CAS  Google Scholar 

  21. Osovsky, R. et al. Continuous-wave pumping of multiexciton bands in the photoluminescence spectrum of a single CdTe–CdSe core–shell colloidal quantum dot. Phys. Rev. Lett. 102, 197401 (2009).

    Article  Google Scholar 

  22. Nasilowski, M., Spinicelli, P., Patriarche, G. & Dubertret, B. Gradient CdSe/CdS quantum dots with room temperature biexciton unity quantum yield. Nano Lett. 15, 3953–3958 (2015).

    Article  CAS  Google Scholar 

  23. Klimov, V. I. et al. Single-exciton optical gain in semiconductor nanocrystals. Nature 447, 441–446 (2007).

    Article  CAS  Google Scholar 

  24. Wang, C., Wehrenberg, B. L., Woo, C. Y. & Guyot-Sionnest, P. Light emission and amplification in charged CdSe quantum dots. J. Phys. Chem. B 108, 9027–9031 (2004).

    Article  CAS  Google Scholar 

  25. Haug, A. Influence of doping on threshold current of semiconductor lasers. Electron. Lett. 21, 792–794 (1985).

    Article  CAS  Google Scholar 

  26. Copeland, J. Heavily-doped semiconductor lasers. IEEE J. Quantum Electron. 17, 2187–2190 (1981).

    Article  Google Scholar 

  27. Rinehart, J. D. et al. Photochemical electronic doping of colloidal CdSe nanocrystals. J. Am. Chem. Soc. 135, 18782–18785 (2013).

    Article  CAS  Google Scholar 

  28. Park, Y.-S. et al. Effect of Auger recombination on lasing in heterostructured quantum dots with engineered core/shell interfaces. Nano Lett. 15, 7319–7328 (2015).

    Article  CAS  Google Scholar 

  29. Cragg, G. E. & Efros, A. L. Suppression of Auger processes in confined structures. Nano Lett. 10, 313–317 (2009).

    Article  Google Scholar 

  30. Bae, W. K. et al. Controlled alloying of the core–shell interface in CdSe/CdS quantum dots for suppression of Auger recombination. ACS Nano 7, 3411–3419 (2013).

    Article  CAS  Google Scholar 

  31. Robel, I. et al. Universal size-dependent trend in Auger recombination in direct-gap and indirect-gap semiconductor nanocrystals. Phys. Rev. Lett. 102, 177404 (2009).

    Article  Google Scholar 

  32. Qin, W. & Guyot-Sionnest, P. Evidence for the role of holes in blinking: negative and oxidized CdSe/CdS dots. ACS Nano 6, 9125–9132 (2012).

    Article  CAS  Google Scholar 

  33. Klimov, V. I. Optical nonlinearities and ultrafast carrier dynamics in semiconductor nanocrystals. J. Phys. Chem. B 104, 6112–6123 (2000).

    Article  CAS  Google Scholar 

  34. Klimov, V. I., McBranch, D. W., Leatherdale, C. A. & Bawendi, M. G. Electron and hole relaxation pathways in semiconductor quantum dots. Phys. Rev. B 60, 13740–13749 (1999).

    Article  CAS  Google Scholar 

  35. Jha, P. P. & Guyot-Sionnest, P. Trion decay in colloidal quantum dots. ACS Nano 3, 1011–1015 (2009).

    Article  CAS  Google Scholar 

  36. Park, Y. -S., Bae, W. K., Pietryga, J. M. & Klimov, V. I. Auger recombination of biexcitons and negative and positive trions in individual quantum dots. ACS Nano 8, 7288–7296 (2014).

    Article  CAS  Google Scholar 

  37. Javaux, C. et al. Thermal activation of non-radiative Auger recombination in charged colloidal nanocrystals. Nat. Nanotech. 8, 206–212 (2013).

    Article  CAS  Google Scholar 

  38. Shim, M. & Guyot-Sionnest, P. n-type colloidal semiconductor nanocrystals. Nature 407, 981–983 (2000).

    Article  CAS  Google Scholar 

  39. Norris, D. J. & Bawendi, M. G. Measurement and assignment of the size-dependent optical spectrum in CdSe quantum dots. Phys. Rev. B 53, 16338–16346 (1996).

    Article  CAS  Google Scholar 

  40. Galland, C. et al. Two types of luminescence blinking revealed by spectroelectrochemistry of single quantum dots. Nature 479, 203–207 (2011).

    Article  CAS  Google Scholar 

  41. Klimov, V. I. Multicarrier interactions in semiconductor nanocrystals in relation to the phenomena of Auger recombination and carrier multiplication. Annu. Rev. Condens. Matter Phys. 5, 285–316 (2014).

    Article  CAS  Google Scholar 

  42. Cohn, A. W. et al. Size dependence of negative trion Auger recombination in photodoped CdSe nanocrystals. Nano Lett. 14, 353–358 (2014).

    Article  CAS  Google Scholar 

  43. Klimov, V. I. in Semiconductor and Metal Nanocrystals: Synthesis and Electronic and Optical Properties, 1st edn, 159–214 (CRC, 2004).

    Google Scholar 

  44. Walsh, B. R. et al. Interfacial electronic structure in graded shell nanocrystals dictates their performance for optical gain. J. Phys. Chem. C 120, 19409–19415 (2016).

    Article  CAS  Google Scholar 

  45. Walsh, B. R. et al. Controlling the surface of semiconductor nanocrystals for efficient light emission from single excitons to multiexcitons. J. Phys. Chem. C 119, 16383–16389 (2015).

    Article  CAS  Google Scholar 

  46. Malak, S. T. et al. Enhancement of optical gain characteristics of quantum dot films by optimization of organic ligands. J. Mater. Chem. C 4, 10069–10081 (2016).

    Article  CAS  Google Scholar 

  47. Bae, W. K. et al. Controlling the influence of Auger recombination on the performance of quantum-dot light-emitting diodes. Nat. Commun. 4, 3661 (2013).

    Google Scholar 

  48. Yang, Y. A., Wu, H., Williams, K. R. & Cao, Y. C. Synthesis of CdSe and CdTe nanocrystals without precursor injection. Angew. Chem. Int. Ed. 44, 6712–6715 (2005).

    Article  CAS  Google Scholar 

  49. Wang, C., Shim, M. & Guyot-Sionnest, P. Electrochromic nanocrystal quantum dots. Science 291, 2390–2392 (2001).

    Article  CAS  Google Scholar 

  50. Koh, W.-K. et al. Heavily doped n-type PbSe and PbS nanocrystals using ground-state charge transfer from cobaltocene. Sci. Rep. 3, 2004 (2013).

    Article  Google Scholar 

Download references

Acknowledgements

Work on the synthesis of core/alloy/shell quantum dots and studies of Auger recombination in synthesized materials were supported by the Chemical Sciences, Biosciences and Geosciences Division, Office of Basic Energy Sciences, Office of Science, US Department of Energy. The studies of the effect of charging on quantum dot optical gain properties were supported by the Laboratory Directed Research and Development (LDRD) programme at Los Alamos National Laboratory (LANL). K.W. acknowledges support by a LANL Director's Postdoctoral Fellowship.

Author information

Author notes

  1. Kaifeng Wu

    Present address: State Key Laboratory of Molecular Reaction Dynamics and Collaborative Innovation, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, China

Authors and Affiliations

  1. Chemistry Division, Los Alamos National Laboratory, Los Alamos, 87545, New Mexico, USA

    Kaifeng Wu, Young-Shin Park, Jaehoon Lim & Victor I. Klimov

  2. Center for High Technology Materials, University of New Mexico, Albuquerque, 87131, New Mexico, USA

    Young-Shin Park

Authors
  1. Kaifeng Wu
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Young-Shin Park
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Jaehoon Lim
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Victor I. Klimov
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

J.L. synthesized the quantum dots and conducted their microstructural characterization. K.W. conducted spectroscopic studies of the effect of charging on quantum dot optical properties. K.W. and Y.-S.P. conducted measurements of amplified spontaneous emission. K.W. and V.I.K. analysed the data and performed modelling of optical-gain performance of charged quantum dots. K.W., Y.-S.P. and V.I.K. performed theoretical modelling of lasing using charged quantum dots. K.W. and V.I.K. wrote the manuscript, with input from the other authors.

Corresponding author

Correspondence to Victor I. Klimov.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary information

Supplementary information (PDF 3135 kb)

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Wu, K., Park, YS., Lim, J. et al. Towards zero-threshold optical gain using charged semiconductor quantum dots. Nature Nanotech 12, 1140–1147 (2017). https://doi.org/10.1038/nnano.2017.189

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nnano.2017.189

This article is cited by

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing