Luminescence determination of donor concentration in n-type 6H-SiC

The low temperature donor-acceptor pair photoluminescence spectra of n-type 6H-SiC has been investigated, both theoretically and experimentally. The excitation intensity dependence of the maximum position and width of the no-phonon line has been observed down to the lowest limit of experimental excitation intensity. We show that the majority impurity (donor) concentration can be obtained from the line-shape of the experimental spectra. The value of the donor concentration found in this way is in good agreement with the result of independent electrical measurements.