Infrared Absorption in Gallium Phosphide

An investigation was made on the infrared absorption spectra of gallium phosphide single crystals doped with different impurities in the temperature range from 90 to 420°K. With decreasing temperature a transformation of the absorption spectrum due to interband transitions between conduction band valleys to the absorption spectrum due to impurity states was observed. On the basis of a theoretical analysis of the results obtained, a number of parameters of the GaP band structure and impurity states characteristics have been determined. [Russian Text Ignored.]