Photoreflectance spectroscopy of CdTe(001) around E1 and E1 %2b Δ1: Linear electro-optic spectrum

We report on the measurement of the linear electro-optic (LEO) reflectance spectrum of CdTe (001) in an energy range around the E1 and E1 %2b Δ1 interband transitions. This spectrum shows a sharp peak localized in energy around E1 and a second shorter peak around E1 %2b Δ1. We show that the theoretical model developed in an earlier article for the LEO line shape of GaAs (001) gives an accurate description of the experimental LEO CdTe spectrum as well. This model includes two contributions to the LEO line shape, a first one proportional to the normalized energy derivative of the reflectance spectrum and a second one associated to the sample reflectance. The large spin-orbit splitting energy of CdTe, (Δ1≈0.6eV) allows for a neat separation of the contributions to the LEO spectrum of the E1 and E1 %2b Δ1 critical points, providing a critical test for the LEO line shape model. From the fitting we obtain d′/d= 1.5 for the conduction band to valence band deformation potential ratio and E2 = 9.1eV for the interband deformation potential in the Brooks notation. © 1999 American Institute of Physics.

VIVO