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

We have studied In + implanted CdTe and Cd sub 0.23HG sub 0.77Te by resonant Raman scattering. The laser excitation was in resonance with the E sub 0 + Delta sub 0 band gap in CdTe or the E sub 1 gap in CD sub 0.23HG sub 0.77Te. Under these conditions dipole forbidden but defect induced 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 10 high 11 to 5x10 high 14ions/square centimetre. The intensity ratio of the one-LO and the two-LO phonon lines is found to be a quantitative measure of the implantation damage in CdTe and Cd sub 0.23Hg sub 0.77Te even for doses as low as 10 high 11ions/square centimetre. 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 res onances in the Raman scattering efficiency.