Defect-induced fundamental edge distoritons in two-photon spectroscopy of semiconductors



The influence of grown-in and impurity defects on the form of the fundamental absorption edge in ZnO, ZnSe and CdS crystal was studied by the method of two-photon absorption (TPA). A considerable long-wavelength shift of the TPA spectra was measured in Zinc-rich compounds after thermal treatment. This can be explained by a very good saturation of interstitial Zni atoms up to a concentration of 1018 cm−3 causing deformation of the band edge.