Zero-Phonon Lines and Phonon Coupling of ZnSe: Mn and CdS: Mn

Absorption and emission spectra of ZnSe: Mn and of CdS: Mn crystals were measured at 4.2^∘{}K. The structure on the absorption and emission bands was identified in terms of phonon emission coupled to one electronic transition in each band. Zero-phonon lines were found in ZnSe: Mn at 18 025, 19 598, and 21 110 cm^-1 and in CdS: Mn at 18 620 cm^-1. They should correspond to the Mn transitions in a cubic crystalline field ⁶A₁→⁴T₁, ⁶A₁→⁴T₂, and ⁶A₁→⁴A₁, ⁴E in ZnSe. The ionic parameters F₂=55454 and F₄=34520 cm^-1 and the value of the crystalline field, $Dq=405$ cm^-1, are deduced for Mn in ZnSe. Principal phonons participating have values of about 70, 94, 160, 209, and 242 cm^-1, which is in agreement with the phonon energies of the ZnSe host lattice.