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Donatas Zigmantas. Portrait.

Donatas Zigmantas

Professor

Donatas Zigmantas. Portrait.

Unraveling the Ultrafast Hot Electron Dynamics in Semiconductor Nanowires

Author

  • Lukas Wittenbecher
  • Emil Viñas Boström
  • Jan Vogelsang
  • Sebastian Lehman
  • Kimberly A. Dick
  • Claudio Verdozzi
  • Donatas Zigmantas
  • Anders Mikkelsen

Summary, in English

Hot electron relaxation and transport in nanostructures involve a multitude of ultrafast processes whose interplay and relative importance are still not fully understood, but which are relevant for future applications in areas such as photocatalysis and optoelectronics. To unravel these processes, their dynamics in both time and space must be studied with high spatiotemporal resolution in structurally well-defined nanoscale objects. We employ time-resolved photoemission electron microscopy to image the relaxation of photogenerated hot electrons within InAs nanowires on a femtosecond time scale. We observe transport of hot electrons to the nanowire surface within 100 fs caused by surface band bending. We find that electron-hole scattering substantially influences hot electron cooling during the first few picoseconds, while phonon scattering is prominent at longer time scales. The time scale of cooling is found to differ between the well-defined wurtzite and zincblende crystal segments of the nanowires depending on excitation light polarization. The scattering and transport mechanisms identified will play a role in the rational design of nanostructures for hot-electron-based applications.

Department/s

  • Chemical Physics
  • Synchrotron Radiation Research
  • NanoLund: Centre for Nanoscience
  • Mathematical Physics
  • Atomic Physics
  • Solid State Physics
  • Centre for Analysis and Synthesis

Publishing year

2021

Language

English

Pages

1133-1144

Publication/Series

ACS Nano

Volume

15

Issue

1

Document type

Journal article

Publisher

The American Chemical Society (ACS)

Topic

  • Condensed Matter Physics (including Material Physics, Nano Physics)

Keywords

  • charge carrier relaxation
  • charge carrier transport
  • Fermi level pinning
  • hot electrons
  • photoemission electron microscopy
  • semiconductor nanowires
  • ultrafast microscopy

Status

Published

ISBN/ISSN/Other

  • ISSN: 1936-0851