EVALUATION OF THE INFRARED ABSORPTION IN nm THICK HEAVILY BORON DOPED Si_(1-x)Ge_x LAYERS ON SILICON

摘要

Infrared absorption due to free carriers have been measured in the spectral range 1.5-25 μm at temperatures of 77 and 300 K on a large variety of heavily p-doped strained Si_(1-x)Ge_x quantum wells on Si. The validity of the usually applied theoretical approaches to describe the spectra has been thoroughly analysed. It is shown that the Boltzmann kinetic equation is invalid under the given experimental conditions. The necessity of a new theory, where the interaction energy of the carriers with the scattering centres would be included already into the energy spectrum of the system, is shown.