A.F. Ioffe Institute of Physics and Technology, Academy of Sciences of the USSR, Leningrad 194021, USSR
Abstract:
Theoretical results are described for the quantitative characterization of impurities by photoelectromagnetic spectroscopy. The diagnostics is based on a study of profiles of spectral lines. Line broadening is caused mainly by the influence of electric fields of charged impurities on neutral donors, in which optical transitions occur. The profile of the spectral line for the intradonor transition between 1s and 2p0 states is calculated taking into account Coulomb correlations in the distribution of charged impurities in space at low temperatures. Calculations were carried out by computer simulation of the impurity system over a wide range of compensation degrees. This parameter can be found by a study of line profile evolution with an increase of temperature. The concentration of donors can then be found by a comparison of the experimental curve with the theoretical line profile for the corresponding degree of compensation. For low compensations an analytical theory is developed for the evolution of line profile with temperature.