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Spin Polarization Dynamics of Free Charge Carriers in CsPbI3 Nanocrystals
- Source :
- Nano Letters. 20:4724-4730
- Publication Year :
- 2020
- Publisher :
- American Chemical Society (ACS), 2020.
-
Abstract
- Lead halide perovskites (LHPs) exhibit large spin-orbit coupling (SOC), leading to only twofold-degenerate valence and conduction bands and therefore allowing for efficient optical orientation. This makes them ideal materials to study charge carrier spins. With this study we elucidate the spin dynamics of photoexcited charge carriers and the underlying spin relaxation mechanisms in CsPbI3 nanocrystals by employing time-resolved differential transmission spectroscopy (DTS). We find that the photoinduced spin polarization significantly diminishes during thermalization and cooling toward the energetically favorable band edge. Temperature-dependent DTS reveals a decay in spin polarization that is more than 1 order of magnitude faster at room temperature (3 ps) than at cryogenic temperatures (32 ps). We propose that spin relaxation of free charge carriers in large-SOC materials like LHPs occurs as a result of carrier-phonon scattering, as described by the Elliott-Yafet mechanism.
- Subjects :
- Valence (chemistry)
Materials science
Condensed matter physics
Spin polarization
Spins
Scattering
Mechanical Engineering
Bioengineering
02 engineering and technology
General Chemistry
Spin–orbit interaction
021001 nanoscience & nanotechnology
Condensed Matter Physics
Condensed Matter::Materials Science
Thermalisation
Condensed Matter::Strongly Correlated Electrons
General Materials Science
Charge carrier
0210 nano-technology
Order of magnitude
Subjects
Details
- ISSN :
- 15306992 and 15306984
- Volume :
- 20
- Database :
- OpenAIRE
- Journal :
- Nano Letters
- Accession number :
- edsair.doi...........c5059fba1db4419d28c382331c3b62a9