Hot-electron dynamics in quantum dots manipulated by spin-exchange Auger interactions

Rohan Singh, Wenyong Liu, Jaehoon Lim, István Robel, Victor I. Klimov

Research output: Contribution to journalArticle

Abstract

The ability to effectively manipulate non-equilibrium ‘hot’ carriers could enable novel schemes for highly efficient energy harvesting and interconversion. In the case of semiconductor materials, realization of such hot-carrier schemes is complicated by extremely fast intraband cooling (picosecond to subpicosecond time scales) due to processes such as phonon emission. Here we show that using magnetically doped colloidal semiconductor quantum dots we can achieve extremely fast rates of spin-exchange processes that allow for ‘uphill’ energy transfer with an energy-gain rate that greatly exceeds the intraband cooling rate. This represents a dramatic departure from the usual situation where energy-dissipation via phonon emission outpaces energy gains due to standard Auger-type energy transfer at least by a factor of three. A highly favourable energy gain/loss rate ratio realized in magnetically doped quantum dots can enable effective schemes for capturing kinetic energy of hot, unrelaxed carriers via processes such as spin-exchange-mediated carrier multiplication and upconversion, hot-carrier extraction and electron photoemission.

Original languageEnglish
Pages (from-to)1035-1041
Number of pages7
JournalNature nanotechnology
Volume14
Issue number11
DOIs
Publication statusPublished - Nov 1 2019

Fingerprint

Hot carriers
Hot electrons
spin exchange
hot electrons
Semiconductor quantum dots
quantum dots
Energy transfer
interactions
Cooling
energy transfer
Energy harvesting
Photoemission
cooling
Kinetic energy
energy
Energy dissipation
Ion exchange
multiplication
Semiconductor materials
photoelectric emission

ASJC Scopus subject areas

  • Bioengineering
  • Atomic and Molecular Physics, and Optics
  • Biomedical Engineering
  • Materials Science(all)
  • Condensed Matter Physics
  • Electrical and Electronic Engineering

Cite this

Hot-electron dynamics in quantum dots manipulated by spin-exchange Auger interactions. / Singh, Rohan; Liu, Wenyong; Lim, Jaehoon; Robel, István; Klimov, Victor I.

In: Nature nanotechnology, Vol. 14, No. 11, 01.11.2019, p. 1035-1041.

Research output: Contribution to journalArticle

Singh, Rohan ; Liu, Wenyong ; Lim, Jaehoon ; Robel, István ; Klimov, Victor I. / Hot-electron dynamics in quantum dots manipulated by spin-exchange Auger interactions. In: Nature nanotechnology. 2019 ; Vol. 14, No. 11. pp. 1035-1041.
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