  It is established experimentally that the low temperature photoelectric
spectra line width of shallow impurities depends not only on charged impurity
concentration $N_i=2KN_A$ and degree of samples compensation $%
  K=N_A/N_D$, as it was believed earlier.To a great extent it depends on the
impurity distribution inhomogeneity also.For samples with homogeneous and
inhomogeneous distribution of impurities line width dependence character on
external electric fields, smaller than break down one, are different.This
broadening mechanism allows to control the quality of samples with nearly equal
impurity concentrations.
