Coherent Spin Dynamics of Electrons and Holes in CsPbBr 3 Colloidal Nanocrystals

Philipp S Grigoryev (1) , Vasilii V Belykh (2) , Dmitri R Yakovlev (2) , Emmanuel Lhuillier (3, 4) , Manfred Bayer (2)

1 St. Petersburg State Technological Institute
2 TU - Technische Universität Dortmund [Dortmund]
3 INSP-E6 - Physico-chimie et dynamique des surfaces
4 INSP - Institut des Nanosciences de Paris

The spin dynamics in CsPbBr 3 lead halide perovskite nanocrystals are studied by picosecond pump−probe Faraday rotation in an external magnetic field. Coherent Larmor precession of electrons and holes with spin dephasing times of ∼600 ps is detected in a transversal magnetic field. The longitudinal spin relaxation time in weak magnetic fields reaches 80 ns at a temperature of 5 K. In this regime, the carrier spin dynamics is governed by nuclear spin fluctuations characterized by an effective hyperfine field strength of 25 mT. The Landéfactors determining the carrier Zeeman splittings are g e = +1.73 for electrons and g h = +0.83 for holes. A comparison with a CsPbBr 3 polycrystalline film and bulk single crystals evidences that the spatial confinement of electrons and holes in the nanocrystals only slightly affects their g factors and spin dynamics.

Mots clés: Metrics & More Article Recommendations Perovskite nanocrystals; CsPbBr 3; coherent spin dynamics; electron and hole g-factors; pump−probe time-resolved Faraday rotation

Domaines: Matière Condensée [cond-mat]

Philipp S Grigoryev, Vasilii V Belykh, Dmitri R Yakovlev, Emmanuel Lhuillier, Manfred Bayer. Coherent Spin Dynamics of Electrons and Holes in CsPbBr 3 Colloidal Nanocrystals. Nano Letters, 2021, ⟨10.1021/acs.nanolett.1c03292⟩. ⟨hal-03360866⟩