Unraveling the Ultrafast Hot Electron Dynamics in Semiconductor Nanowires
- Resource Type
- Authors
- Donatas Zigmantas; Jan Vogelsang; Anders Mikkelsen; Kimberly A. Dick; Emil Viñas Boström; Claudio Verdozzi; Sebastian Lehman; Lukas Wittenbecher
- Source
- ACS Nano
- Subject
- Materials science
Nanowire
General Physics and Astronomy
Physics::Optics
02 engineering and technology
010402 general chemistry
01 natural sciences
Article
Condensed Matter::Materials Science
photoemission electron microscopy
General Materials Science
Fermi level pinning
Wurtzite crystal structure
semiconductor nanowires
Phonon scattering
Scattering
business.industry
Relaxation (NMR)
General Engineering
021001 nanoscience & nanotechnology
Condensed Matter::Mesoscopic Systems and Quantum Hall Effect
0104 chemical sciences
Photoemission electron microscopy
Semiconductor
Chemical physics
charge carrier transport
Femtosecond
charge carrier relaxation
ultrafast microscopy
0210 nano-technology
business
hot electrons
- Language
- English
- ISSN
- 1936-086X
1936-0851
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.