Coherent Spin Dynamics of Electrons in CsPbBr3 Perovskite Nanocrystals at Room Temperature

Coherent spin dynamics of charge carriers in CsPbBr3 perovskite nanocrystals are studied in a temperature range of 4-300 K and in magnetic fields of up to 500 mT using time-resolved pump-probe Faraday rotation and differential transmission techniques. We detect electron spin Larmor precession in the entire temperature range. At temperatures below 50 K, hole spin precession is also observed. The temperature dependences of spin-related parameters, such as Lande g-factor and spin dephasing time are measured and analyzed. The electron g-factor increases with growing temperature, which can not be described by the temperature-induced band gap renormalization. We find that photocharging of the nanocrystals with either electrons or holes depends on the sample cooling regime, namely the cooling rate and illumination conditions. The type of the charge carrier provided by the photocharging can be identified via the carrier spin Larmor precession.

Automated summary

Coherent spin dynamics of charge carriers in CsPbBr3 perovskite nanocrystals were investigated using time-resolved pump-probe Faraday rotation and differential transmission techniques in a temperature range of 4-300 K and magnetic fields up to 500 mT. Electron spin Larmor precession was observed throughout the temperature range, and hole spin precession was also observed at temperatures below 50 K. The temperature dependence of spin-related parameters, such as Lande g-factor and spin dephasing time, were measured and analyzed. Photocharging of the nanocrystals with either electrons or holes was found to depend on the sample cooling regime, and the type of charge carrier could be identified through carrier spin Larmor precession.