Coherent Spin Dynamics of Electrons and Holes in CsPbBr3 Colloidal Nanocrystals

The spin dynamics in CsPbBr3 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 similar to 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 Lande factors determining the carrier Zeeman splittings are g(e) = +1.73 for electrons and g(h) = +0.83 for holes. A comparison with a CsPbBr3 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.

Automated summary

The spin dynamics of electrons and holes in CsPbBr3 lead halide perovskite nanocrystals were studied using picosecond pump-probe Faraday rotation in an external magnetic field. The study revealed coherent Larmor precession of electrons and holes, as well as longitudinal spin relaxation in weak magnetic fields. Additionally, the impact of nuclear spin fluctuations on carrier spin dynamics was also explored.