Resonant Brillouin Scattering of Exciton Polaritons in 2H-PbI₂

Abstract

Resonant Brillouin scattering spectra are measured on a layer semiconductor 2H-PbI₂. The observed exciton polariton dispersion in the direction parallel to the c-axis is interpreted by a two branch polariton model yielding the translational exciton mass of 2.3 m₀ and the effective dielectric constant of 10. The anisotropy of the effective mass is estimated to be m_⁄⁄⁄m_⊥=3.4 for exciton and 4.4 for conduction electron, respectively.