Spin-flip Raman scattering of bright excitons in CdSe nanocrystals in a glass matrix
Phys. Rev. B 112, 035304 – Published 16 July, 2025
DOI: https://doi.org/10.1103/8sp3-1xyc
Abstract
The exciton states in wurtzite CdSe nanocrystals (NCs) embedded in a glass matrix are examined by spin-flip Raman scattering using resonant excitation at magnetic fields up to 8 T. The Landé factors of the bright excitons of about 2.2 are found to be weakly dependent on the NC diameter in the range of . For an explanation of the experimental results, a theory of acoustic phonon-assisted exciton spin flips is developed, and the exciton spin relaxation rates are calculated. The theory is used to model the spin-flip Raman spectra of spherical CdSe NCs, taking into account their random orientation and size dispersion in the ensemble. Our calculations show that, despite the strong anisotropy of the exciton factors and the random NC orientation, the spin-flip Raman shifts are determined by the NCs whose wurtzite axis is oriented along the magnetic field. The model results are in good agreement with our experimental data. From fitting the experimental data, the hole factor is extracted.
