Theoretical treatment of the resonant hyper-Raman effect in a CdS crystal

Abstract

A theoretical analysis for the resonant hyper-Raman scattering (RHRS) of light in a CdS crystal is presented. The different scattering mechanisms are considered and the cross section of the RHRS by LO phonons are calculated as a function of incident frequency.

Two-phonon resonant hyper-Raman scattering treatment in a CdS crystal

“…Theoretical analysis for the first-order HRS observed was performed by us [21]. It has been shown that the mea- sured frequency dependence of the intensity of the HRS by 1LO phonons agrees with the resonance profile calculated for the hyper-Raman process caused by the twophoton transition to a s-exciton state [21].…”

“…In calculations we used the crystal parameters given in [21]. Also we took into account that this mechanism of the 2LO-scattering is weakly dependent on q LS [11].…”

Theoretical treatment of the first-order hyper-Raman scattering in semiconductors

“…Besides, the forbidden Fröhlich interaction of the LO-phonons with the s-excitons of the B and C series can contribute to the HRS process too. Similar calculations of the frequency dependency of the cross section were earlier performed us, taking into account the resonant scattering process only20 . In this work the non-resonant contribution, ignored.…”

“…In this work the non-resonant contribution, ignored. By using the crystal parameters given in Ref 20,. we carried out calculation of S HR under two-photon excitation below and in the range of the excitonic resonances.…”

The Raman and hyper-Raman scatterings of light by LO-phonons in a CdS crystal under excitation near resonance with the An=2and Bn=1exciton levels

“…In particular, an increase in the HRS intensity was observed in a CdS crystal when the doubled frequency of the exciting radiation approached the exciton resonance region [10]. Later, this phenomenon was explained by the scattering mechanism caused by two-photon transitions into excitons of the s-type [11]. In recent years, the HRS spectroscopy was applied to study complex molecules [12,13], quantum dots [14], and nanoparticulates [15].…”