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High-efficiency photoemission from magnetically doped quantum dots driven by multi-step spin-exchange Auger ionization

Nature Photonics volume 16, pages 433–440 (2022)Cite this article

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Abstract

Materials displaying electron photoemission under visible-light excitation are of great interest for applications in photochemistry, photocathodes, advanced electron beam sources and electron microscopy. We demonstrate that in manganese-doped CdSe colloidal quantum dots (CQDs), two-step Auger up-conversion enables highly efficient electron photoemission under excitation with visible-light pulses. This effect is enabled by extremely fast, subpicosecond Auger-type energy transfer from excited manganese ions to an intrinsic CQD exciton. Since the rate of this process outpaces that of intraband cooling, the high-energy ‘hot’ electron produced by the first Auger-excitation step can be efficiently promoted further into the external ‘vacuum’ state via one more manganese-to-CQD energy-transfer step. This CQD ionization pathway exploits exceptionally large uphill energy gain rates associated with the spin-exchange Auger process and leads to photoemission efficiencies of more than 3%, orders of magnitude greater than in the case of undoped CQDs. We demonstrate that using this phenomenon, we can achieve high-yield production of solvated electrons (>3% internal quantum efficiency), which makes it of considerable utility in visible-light-driven reduction photochemistry.

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Fig. 1: Mechanisms for Auger-assisted photoemission and spin-exchange excitation transfer.
Fig. 2: Optical spectra and PL dynamics of undoped and Mn-doped CdSe/CdS CQDs.
Fig. 3: Auger recombination in Mn-doped and undoped CdSe/CdS CQDs.
Fig. 4: Experimental observations of electron photoemission from Mn-doped CdSe/CdS CQDs (sample s13).
Fig. 5: Generation of SEs using water-dispersed Mn-doped CdSe/CdS CQDs.

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Data availability

Source data are provided for Figs. 2–5. The rest of the data are available from the corresponding author upon reasonable request. Source data are provided with this paper.

References

  1. Rosencher, E. Optoelectronics (Cambridge Univ. Press, 2002).

  2. Rogalski, A. Infrared detectors: an overview. Infrared Phys. Technol. 43, 187–210 (2002).

    Article  ADS  Google Scholar 

  3. Fujishima, A. & Honda, K. Electrochemical photolysis of water at a semiconductor electrode. Nature 238, 37–38 (1972).

    Article  ADS  Google Scholar 

  4. Kalanur, S. S. & Seo, H. in Methods for Electrocatalysis: Advanced Materials and Allied Applications (eds Inamuddin et al.) 171–199 (Springer, 2020).

  5. Sahara, G. et al. Photoelectrochemical reduction of CO2 coupled to water oxidation using a photocathode with a Ru(II)–Re(I) complex photocatalyst and a CoOx/TaON photoanode. J. Am. Chem. Soc. 138, 14152–14158 (2016).

    Article  Google Scholar 

  6. Schreier, M. et al. Efficient and selective carbon dioxide reduction on low cost protected Cu2O photocathodes using a molecular catalyst. Energy Environ. Sci. 8, 855–861 (2015).

    Article  Google Scholar 

  7. Morishita, H., Ohshima, T., Kuwahara, M., Ose, Y. & Agemura, T. Resolution improvement of low-voltage scanning electron microscope by bright and monochromatic electron gun using negative electron affinity photocathode. J. Appl. Phys. 127, 164902 (2020).

    Article  ADS  Google Scholar 

  8. Kong, S. H., Kinross-Wright, J., Nguyen, D. C. & Sheffield, R. L. Photocathodes for free electron lasers. Nucl. Instrum. Methods Phys. Res. A 358, 272–275 (1995).

    Article  ADS  Google Scholar 

  9. Moody, N. A. et al. Perspectives on designer photocathodes for X-ray free-electron lasers: influencing emission properties with heterostructures and nanoengineered electronic states. Phys. Rev. Appl. 10, 047002 (2018).

    Article  ADS  Google Scholar 

  10. Einstein, A. On a heuristic point of view concerning the production and transformation of light. Ann. Phys. 17, 132–148 (1905).

    Article  Google Scholar 

  11. Landsberg, P. T. Recombination in Semiconductors (Cambridge Univ. Press, 1992).

  12. Klimov, V. I., Mikhailovsky, A. A., McBranch, D. W., Leatherdale, C. A. & Bawendi, M. G. Quantization of multiparticle Auger rates in semiconductor quantum dots. Science 287, 1011–1013 (2000).

    Article  ADS  Google Scholar 

  13. 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  ADS  Google Scholar 

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

    Article  Google Scholar 

  15. Makarov, N. S., Lin, Q., Pietryga, J. M., Robel, I. & Klimov, V. I. Auger up-conversion of low-intensity infrared light in engineered quantum dots. ACS Nano 10, 10829–10841 (2016).

    Article  Google Scholar 

  16. Semonin, O. E. et al. Peak external photocurrent quantum efficiency exceeding 100% via MEG in a quantum dot solar cell. Science 334, 1530–1533 (2011).

    Article  ADS  Google Scholar 

  17. Gao, J., Fidler, A. F. & Klimov, V. I. Carrier multiplication detected through transient photocurrent in device-grade films of lead selenide quantum dots. Nat. Commun. 6, 8185 (2015).

    ADS  Google Scholar 

  18. Livache, C. et al. Band edge dynamics and multiexciton generation in narrow band gap HgTe nanocrystals. ACS Appl. Mater. Interfaces 10, 11880–11887 (2018).

    Article  Google Scholar 

  19. Makarov, N. S. et al. Quantum dot thin-films as rugged, high-performance photocathodes. Nano Lett. 17, 2319–2327 (2017).

    Article  ADS  Google Scholar 

  20. Melnychuk, C. & Guyot-Sionnest, P. Multicarrier dynamics in quantum dots. Chem. Rev. 121, 2325–2372 (2021).

    Article  Google Scholar 

  21. Klimov, V. I. & McBranch, D. W. Femtosecond 1P-to-1S electron relaxation in strongly confined semiconductor nanocrystals. Phys. Rev. Lett. 80, 4028–4031 (1998).

    Article  ADS  Google Scholar 

  22. 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  ADS  Google Scholar 

  23. Chen, H.-Y. et al. Hot electrons from consecutive exciton–Mn energy transfer in Mn-doped semiconductor nanocrystals. J. Phys. Chem. C 115, 11407–11412 (2011).

    Article  Google Scholar 

  24. Barrows, C. J. et al. Electrical detection of quantum dot hot electrons generated via a Mn2+-enhanced Auger process. J. Phys. Chem. Lett. 8, 126–130 (2017).

    Article  Google Scholar 

  25. Singh, R., Liu, W., Lim, J., Robel, I. & Klimov, V. I. Hot-electron dynamics in quantum dots manipulated by spin-exchange Auger interactions. Nat. Nanotechnol. 14, 1035–1041 (2019).

    Article  ADS  Google Scholar 

  26. Alig, R. C. & Bloom, S. Electron-hole-pair creation energies in semiconductors. Phys. Rev. Lett. 35, 1522–1525 (1975).

    Article  ADS  Google Scholar 

  27. Peng, B., Liang, W., White, M. A., Gamelin, D. R. & Li, X. Theoretical evaluation of spin-dependent Auger de-excitation in Mn2+-doped semiconductor nanocrystals. J. Phys. Chem. C 116, 11223–11231 (2012).

    Article  Google Scholar 

  28. Jin, H., Goryca, M., Janicke, M. T., Crooker, S. A. & Klimov, V. I. Exploiting functional impurities for fast and efficient incorporation of manganese into quantum sots. J. Am. Chem. Soc. 142, 18160–18173 (2020).

    Article  Google Scholar 

  29. Crooker, S. A., Barrick, T., Hollingsworth, J. A. & Klimov, V. I. Multiple temperature regimes of radiative decay in CdSe nanocrystal quantum dots: intrinsic limits to the dark-exciton lifetime. Appl. Phys. Lett. 82, 2793–2795 (2003).

    Article  ADS  Google Scholar 

  30. de Mello Donegá, C., Bode, M. & Meijerink, A. Size- and temperature-dependence of exciton lifetimes in CdSe quantum dots. Phys. Rev. B 74, 085320 (2006).

    Article  ADS  Google Scholar 

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

    Article  Google Scholar 

  32. Robel, I., Gresback, R., Kortshagen, U., Schaller, R. D. & Klimov, V. I. Universal size-dependent trend in Auger recombination in direct-gap and indirect-gap semiconductor nanocrystals. Phys. Rev. Lett. 102, 177404 (2009).

    Article  ADS  Google Scholar 

  33. Klimov, V. I. & McBranch, D. W. Auger-process-induced charge separation in semiconductor nanocrystals. Phys. Rev. B 55, 13173–13179 (1997).

    Article  ADS  Google Scholar 

  34. Jou, F.-Yuan & Freeman, G. R. Temperature and isotope effects on the shape of the optical absorption spectrum of solvated electrons in water. J. Phys. Chem. 83, 2383–2387 (1979).

    Article  Google Scholar 

  35. Herbert, J. M. & Coons, M. P. The hydrated electron. Annu. Rev. Phys. Chem. 68, 447–472 (2017).

    Article  ADS  Google Scholar 

  36. Hart, E. J., Michael, B. D. & Schmidt, K. H. Absorption spectrum of eaq− in the temperature range −4 to 390°. J. Phys. Chem. 75, 2798–2805 (1971).

    Article  Google Scholar 

  37. Mazzacurati, V. & Signorelli, G. On the absorption cross-section of solvated electrons. Lett. Nuovo Cimento 12, 347–350 (1975).

    Article  Google Scholar 

  38. Zhu, D., Zhang, L., Ruther, R. E. & Hamers, R. J. Photo-illuminated diamond as a solid-state source of solvated electrons in water for nitrogen reduction. Nat. Mater. 12, 836–841 (2013).

    Article  ADS  Google Scholar 

  39. Lapointe, F., Wolf, M., Campen, R. K. & Tong, Y. Probing the birth and ultrafast dynamics of hydrated electrons at the gold/liquid water interface via an optoelectronic approach. J. Am. Chem. Soc. 142, 18619–18627 (2020).

    Article  Google Scholar 

  40. Vlaskin, V. A., Janssen, N., van Rijssel, J., Beaulac, R. & Gamelin, D. R. Tunable dual emission in doped semiconductor nanocrystals. Nano Lett. 10, 3670–3674 (2010).

    Article  ADS  Google Scholar 

  41. Li, J. J. et al. Large-scale synthesis of nearly monodisperse CdSe/CdS core/shell nanocrystals using air-stable reagents via successive ion layer adsorption and reaction. J. Am. Chem. Soc. 125, 12567–12575 (2003).

    Article  Google Scholar 

  42. Kozlov, O. V. et al. Sub-single-exciton lasing using charged quantum dots coupled to a distributed feedback cavity. Science 365, 672–675 (2019).

    Article  ADS  Google Scholar 

Download references

Acknowledgements

These studies were supported by the Solar Photochemistry Program of the Chemical Sciences, Biosciences and Geosciences Division, Office of Basic Energy Sciences, Office of Science, US Department of Energy.

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Authors and Affiliations

  1. Chemistry Division, C-PCS, Los Alamos National Laboratory, Los Alamos, NM, USA

    Clément Livache, Whi Dong Kim, Ho Jin, Oleg V. Kozlov, Igor Fedin & Victor I. Klimov

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

    Ho Jin

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Contributions

V.I.K. conceived the idea and coordinated the overall research effort. H.J. synthesized the Mn-doped CQDs and characterized their PL properties. I.F. fabricated the reference undoped CQDs. C.L. and O.V.K. conducted the TA studies and analysed the spectroscopic data. W.D.K. and C.L. conducted the SE experiments and analysed the data. C.L. and V.I.K wrote the manuscript with inputs from other authors.

Corresponding author

Correspondence to Victor I. Klimov.

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Nature Photonics thanks Freddy Rabouw and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Supplementary information

Supplementary Information

Supplementary Figs. 1–9, Table 1 and refs.

Source data

Source Data Fig. 2

Sample spectra, time-resolved PL traces.

Source Data Fig. 3

1S state bleach dynamics for s0 and s13.

Source Data Fig. 4

Transient spectra for s13 and estimations of photoemission efficiencies.

Source Data Fig. 5

SE spectra and SE generation efficiency.

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Livache, C., Kim, W.D., Jin, H. et al. High-efficiency photoemission from magnetically doped quantum dots driven by multi-step spin-exchange Auger ionization. Nat. Photon. 16, 433–440 (2022). https://doi.org/10.1038/s41566-022-00989-x

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