A theoretical study to a polarization catastrophe in doped semiconductors

Abstract

A theoretical prediction of the absorption spectra in n-doped semiconductors due to donor pairs is extended further to investigate its contribution to the refractive index of phosphorus-doped silicon. Such a contribution yields a polarization catastrophe at the metal-nonmetal transition. The altemant molecular orbital with a many-valley character of the host material is used in the calculation. The results show good agreement with experiments.