Implantation effects on resonant Raman scattering in CdTe and Cd0.23Hg0.77Te

Abstract

We have studied In+ implanted CdTe and Cd0.23Hg0.77Te by resonant Raman scattering. The laser excitation was in resonance with the EO + ΔO band gap in CdTe or the E1 gap in Cd0.23Hg0.77Te. Under these conditions dipole forbidden but defect ind scattering by one longitudinal optical (LO) phonon as well as Fröhlich-induced two-LO phonon scattering is observed. In both cases scattering is found to be strongly affected by ion implantation. In+ was implanted at an ion energy of 350 keV with doses ranging from 1011 to 5×1014 ions/cm2. The intensity ratio of the one-LO phonon lines is found to be a quantitative measure of the implantation damage in CdTe and Cd0.23Hg0.77Te even for doses as low as 1011 ions/cm2. It is shown that the observed effects of implantation damage on resonant Raman scattering by LO phonons are due to a broadening and an energy shift of the corresponding resonances in the Raman scattering efficiency. © 1989.