The observed D-band photoluminescence spectra of deformed SixGe1-x alloys, with x-values ranging from 0.4 to 1.0, were studied. The alloy crystals were grown by using the Czochralski method. The luminescence centers were generated by deformation of the alloy, as in the cases of pure Si and Ge. The number of lines in the D-band spectrum changed from 4 to 2 as the Si content decreased. The dependences of the peak positions of the D1 and D2 lines upon the composition were different to those of the D3 and D4 lines. Thus, the D-band spectrum changed from Si-like to Ge-like at an x-value of about 0.5. The D1 and D4 lines appeared to predominate at x-values of less than 0.5, and corresponded to bands I and II of deformed Ge. The peak positions of the D1 and D2 lines depended upon the deformation and annealing temperatures. This was characteristic of the alloy crystal, and was not observed in the cases of pure Si or Ge. The behavior was attributed to differences in the shape of the dislocations, and to differences in composition near to the core of the dislocations.

K.Tanaka, A.Matui, M.Suezawa, K.Sumino: Materials Science Forum, 1995, 196-201, 377-82