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Quantum dot solids showing state-resolved band-like transport

Nature Materials volume 19, pages 323–329 (2020)Cite this article

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Abstract

Improving charge mobility in quantum dot (QD) films is important for the performance of photodetectors, solar cells and light-emitting diodes. However, these applications also require preservation of well defined QD electronic states and optical transitions. Here, we present HgTe QD films that show high mobility for charges transported through discrete QD states. A hybrid surface passivation process efficiently eliminates surface states, provides tunable air-stable n and p doping and enables hysteresis-free filling of QD states evidenced by strong conductance modulation. QD films dried at room temperature without any post-treatments exhibit mobility up to μ ~ 8 cm2 V−1 s−1 at a low carrier density of less than one electron per QD, band-like behaviour down to 77 K, and similar drift and Hall mobilities at all temperatures. This unprecedented set of electronic properties raises important questions about the delocalization and hopping mechanisms for transport in QD solids, and introduces opportunities for improving QD technologies.

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Fig. 1: HgTe QDs.
Fig. 2: State filling in HgTe QD FETs.
Fig. 3: Charge transport studies of 13.1 ± 1.1 nm HgTe QD solids.
Fig. 4: Hall effect, Seebeck effect and photoconductivity of HgTe QD films.

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Data availability

The data sets generated and analysed during the current study are available from the corresponding author on reasonable request. Source data for Figs. 1–4 are provided with the paper.

References

  1. Kagan, C. R., Lifshitz, E., Sargent, E. H. & Talapin, D. V. Building devices from colloidal quantum dots. Science 353, aac5523 (2016).

    Google Scholar 

  2. Tang, X., Ackerman, M. M., Chen, M. & Guyot-Sionnest, P. Dual-band infrared imaging using stacked colloidal quantum dot photodiodes. Nat. Photon. 13, 277–282 (2019).

    CAS  Google Scholar 

  3. Li, X. et al. Bright colloidal quantum dot light-emitting diodes enabled by efficient chlorination. Nat. Photon. 12, 159–164 (2018).

    CAS  Google Scholar 

  4. Lee, J.-S., Kovalenko, M. V., Huang, J., Chung, D. S. & Talapin, D. V. Band-like transport, high electron mobility and high photoconductivity in all-inorganic nanocrystal arrays. Nat. Nanotechnol. 6, 348–352 (2011).

    CAS  Google Scholar 

  5. Talgorn, E. et al. Unity quantum yield of photogenerated charges and band-like transport in quantum-dot solids. Nat. Nanotechnol. 6, 733–739 (2011).

    CAS  Google Scholar 

  6. Choi, J.-H. et al. Bandlike transport in strongly coupled and doped quantum dot solids: a route to high-performance thin-film electronics. Nano Lett. 12, 2631–2638 (2012).

    CAS  Google Scholar 

  7. Kagan, C. R. & Murray, C. B. Charge transport in strongly coupled quantum dot solids. Nat. Nanotechnol. 10, 1013 (2015).

    CAS  Google Scholar 

  8. Chen, T. et al. Metal–insulator transition in films of doped semiconductor nanocrystals. Nat. Mater. 15, 299 (2015).

    Google Scholar 

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

    CAS  Google Scholar 

  10. Greenberg, B. L. et al. ZnO nanocrystal networks near the insulator–metal transition: tuning contact radius and electron density with intense pulsed light. Nano Lett. 17, 4634–4642 (2017).

    CAS  Google Scholar 

  11. Roest, A. L., Kelly, J. J., Vanmaekelbergh, D. & Meulenkamp, E. A. Staircase in the electron mobility of a ZnO quantum dot assembly due to shell filling. Phys. Rev. Lett. 89, 036801 (2002).

    CAS  Google Scholar 

  12. Yu, D., Wang, C. & Guyot-Sionnest, P. n-type conducting CdSe nanocrystal solids. Science 300, 1277–1280 (2003).

    CAS  Google Scholar 

  13. Chen, M. & Guyot-Sionnest, P. Reversible electrochemistry of mercury chalcogenide colloidal quantum dot films. ACS Nano 11, 4165–4173 (2017).

    CAS  Google Scholar 

  14. Yu, D., Wang, C., Wehrenberg, B. L. & Guyot-Sionnest, P. Variable range hopping conduction in semiconductor nanocrystal solids. Phys. Rev. Lett. 92, 216802 (2004).

    Google Scholar 

  15. Nika, D. L., Pokatilov, E. P., Shao, Q. & Balandin, A. A. Charge-carrier states and light absorption in ordered quantum dot superlattices. Phys. Rev. B 76, 125417 (2007).

    Google Scholar 

  16. Shabaev, A., Efros, A. L. & Efros, A. L. Dark and photo-conductivity in ordered array of nanocrystals. Nano Lett. 13, 5454–5461 (2013).

    CAS  Google Scholar 

  17. Whitham, K. et al. Charge transport and localization in atomically coherent quantum dot solids. Nat. Mater. 15, 557 (2016).

    CAS  Google Scholar 

  18. Guyot-Sionnest, P. Electrical transport in colloidal quantum dot films. J. Phys. Chem. Lett. 3, 1169–1175 (2012).

    CAS  Google Scholar 

  19. Keuleyan, S. E., Guyot-Sionnest, P., Delerue, C. & Allan, G. Mercury telluride colloidal quantum dots: electronic structure, size-dependent spectra, and photocurrent detection up to 12 μm. ACS Nano 8, 8676–8682 (2014).

    CAS  Google Scholar 

  20. Goubet, N. et al. Terahertz HgTe nanocrystals: beyond confinement. J. Am. Chem. Soc. 140, 5033–5036 (2018).

    CAS  Google Scholar 

  21. Hudson, M. H. et al. Conduction band fine structure in colloidal HgTe quantum dots. ACS Nano 12, 9397–9404 (2018).

    CAS  Google Scholar 

  22. Allan, G. & Delerue, C. Tight-binding calculations of the optical properties of HgTe nanocrystals. Phys. Rev. B 86, 165437 (2012).

    Google Scholar 

  23. Shen, G., Chen, M. & Guyot-Sionnest, P. Synthesis of nonaggregating HgTe colloidal quantum dots and the emergence of air-stable n-doping. J. Phys. Chem. Lett. 8, 2224–2228 (2017).

    CAS  Google Scholar 

  24. Kovalenko, M. V., Scheele, M. & Talapin, D. V. Colloidal nanocrystals with molecular metal chalcogenide surface ligands. Science 324, 1417–1420 (2009).

    CAS  Google Scholar 

  25. Shklovskii, B. I. & Efros, A. L. Electronic Properties of Doped Semiconductors (Springer, 1984).

  26. Chu, I.-H., Radulaski, M., Vukmirovic, N., Cheng, H.-P. & Wang, L.-W. Charge transport in a quantum dot supercrystal. J. Phys. Chem. C 115, 21409–21415 (2011).

    CAS  Google Scholar 

  27. Prodanović, N., Vukmirović, N., Ikonić, Z., Harrison, P. & Indjin, D. Importance of polaronic effects for charge transport in CdSe quantum dot solids. J. Phys. Chem. Lett. 5, 1335–1340 (2014).

    Google Scholar 

  28. Reich, K. V., Chen, T. & Shklovskii, B. I. Theory of a field-effect transistor based on a semiconductor nanocrystal array. Phys. Rev. B 89, 235303 (2014).

    Google Scholar 

  29. Beverly, K. C. et al. Quantum dot artificial solids: understanding the static and dynamic role of size and packing disorder. Proc. Natl Acad. Sci. USA 99, 6456–6459 (2002).

    CAS  Google Scholar 

  30. Fratini, S., Mayou, D. & Ciuchi, S. The transient localization scenario for charge transport in crystalline organic materials. Adv. Funct. Mater. 26, 2292–2315 (2016).

    CAS  Google Scholar 

  31. Kang, S. D. & Snyder, G. J. Charge-transport model for conducting polymers. Nat. Mater. 16, 252–257 (2016).

    Google Scholar 

  32. Kaiser, A. B. Electronic transport properties of conducting polymers and carbon nanotubes. Rep. Prog. Phys. 64, 1–49 (2000).

    Google Scholar 

  33. Sirringhaus, H., Sakanoue, T. & Chang, J.-F. Charge-transport physics of high-mobility molecular semiconductors. Phys. Status Solidi B 249, 1655–1676 (2012).

    CAS  Google Scholar 

  34. Uemura, T. et al. Temperature dependence of the Hall effect in pentacene field-effect transistors: possibility of charge decoherence induced by molecular fluctuations. Phys. Rev. B 85, 035313 (2012).

    Google Scholar 

  35. Yi, H. T., Gartstein, Y. N. & Podzorov, V. Charge carrier coherence and Hall effect in organic semiconductors. Sci. Rep. 6, 23650 (2016).

    CAS  Google Scholar 

  36. Chang, J.-F. et al. Hall-effect measurements probing the degree of charge-carrier delocalization in solution-processed crystalline molecular semiconductors. Phys. Rev. Lett. 107, 066601 (2011).

    Google Scholar 

  37. Wang, S., Ha, M., Manno, M., Daniel Frisbie, C. & Leighton, C. Hopping transport and the Hall effect near the insulator–metal transition in electrochemically gated poly(3-hexylthiophene) transistors. Nat. Commun. 3, 1210 (2012).

    Google Scholar 

  38. Meton, M. & Gerard, P. Hall effect in dilute electrolytes. Chem. Phys. Lett. 44, 582–585 (1976).

    CAS  Google Scholar 

  39. Holstein, T. Hall effect in impurity conduction. Phys. Rev. 124, 1329–1347 (1961).

    Google Scholar 

  40. Chien, C. L. & Westgate, C. R. The Hall Effect and its Applications (Plenum, 1980).

  41. Klein, R. S. Investigation of the Hall effect in impurity-hopping conduction. Phys. Rev. B 31, 2014–2021 (1985).

    CAS  Google Scholar 

  42. Kang, S. D., Dylla, M. & Snyder, G. J. Thermopower-conductivity relation for distinguishing transport mechanisms: polaron hopping in CeO2 and band conduction in SrTiO3. Phys. Rev. B 97, 235201 (2018).

    CAS  Google Scholar 

  43. Kaiser, A. B. Thermoelectric power and conductivity of heterogeneous conducting polymers. Phys. Rev. B 40, 2806–2813 (1989).

    CAS  Google Scholar 

  44. Burns, M. J. & Chaikin, P. M. Interaction effects and thermoelectric power in low-temperature hopping. J. Phys. C: Solid State Phys. 18, L743–L749 (1985).

    CAS  Google Scholar 

  45. Troisi, A. The speed limit for sequential charge hopping in molecular materials. Org. Electron. 12, 1988–1991 (2011).

    CAS  Google Scholar 

  46. Ong, W.-L., Rupich, S. M., Talapin, D. V., McGaughey, A. J. H. & Malen, J. A. Surface chemistry mediates thermal transport in three-dimensional nanocrystal arrays. Nat. Mater. 12, 410 (2013).

    CAS  Google Scholar 

  47. Rosencher, E. & Vinter, B. Optoelectronics (Cambridge Univ. Press, 2002).

  48. Chen, M. et al. High carrier mobility in HgTe quantum dot solids improves mid-IR photodetectors. ACS Photon. 6, 2358 (2019).

    Google Scholar 

Download references

Acknowledgements

This work was supported by the University of Chicago Materials Research Science and Engineering Center, which is funded by the NSF under award number DMR-1420709, by the Defense Advanced Research Projects Agency (DARPA) as a subcontract to Voxtel, Inc. for the Wired program, by the Department of Defense (DOD) Air Force Office of Scientific Research under grant number FA9550-18-1-0099 and by the National Science Foundation under grant DMR-1708378.

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Author notes

  1. These authors contributed equally: Xinzheng Lan, Menglu Chen.

Authors and Affiliations

  1. Department of Chemistry and James Franck Institute, University of Chicago, Chicago, IL, USA

    Xinzheng Lan, Menglu Chen, Margaret H. Hudson, Vladislav Kamysbayev, Yuanyuan Wang, Philippe Guyot-Sionnest & Dmitri V. Talapin

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Contributions

M.H.H. carried out experiments on QD synthesis. X.L. and Y.W. developed the methods for ligands exchange. V.K. carried out SAXS measurements and data analysis. X.L. and M.C. prepared thin-film devices and carried out charge-transport experiments. X.L., M.C., P.G.-S. and D.V.T. performed the analysis of the transport data. The manuscript was written by D.V.T. and P.G.-S. All the authors discussed the results and commented on the manuscript.

Corresponding authors

Correspondence to Philippe Guyot-Sionnest or Dmitri V. Talapin.

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The authors declare no competing interests.

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Supplementary information

Supplementary Information

Supplementary materials and methods, Discussion 1–10, Tables 1–5 and Figs. 1–19.

Source data

Source Data Fig. 1

Unprocessed Fourier-transform infrared absorption spectra of undoped and n-type doped 12.5 ± 1.0 nm HgTe QDs and fitting. SAXS data and fitting.

Source Data Fig. 2

Unprocessed FET transport data of HgTe and intraband spectra.

Source Data Fig. 3

Mobility as a function of temperature.

Source Data Fig. 4

Hall voltage, Seebeck coefficient, Hall mobility and FET mobility at different temperatures. Photoresponse data.

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Lan, X., Chen, M., Hudson, M.H. et al. Quantum dot solids showing state-resolved band-like transport. Nat. Mater. 19, 323–329 (2020). https://doi.org/10.1038/s41563-019-0582-2

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