It was found that the photoluminescence spectra of deformed bulk Si-Ge alloys exhibited strange peak shifts of the D1 and D2 lines; depending upon the deformation and annealing temperatures. Czochralski crystal specimens were deformed in compression, at temperatures of between 700 and 900C, in an Ar atmosphere. The photoluminescence spectra were measured at 4.2K. It was noted that the peak positions of the D1 and D2 lines depended upon the deformation temperature. They were at higher energies for higher deformation temperatures. However, the results for D3 and D4 did not depend upon the deformation temperature. The magnitudes of the peak shifts of the D1 and D2 lines were proportional to t2/3, at small t, during isothermal annealing at about 650C. Here, t was the annealing time. The activation energy was estimated to be equal to 2.5eV. This was much smaller than the value for self-diffusion. These results were explained in terms of a change in alloy composition, around dislocations, which was caused by elastic interactions between the dislocations and Si or Ge atoms. Point defects which were generated during deformation were thought to play a crucial role in the latter process.

K.Tanaka, M.Suezawa, I.Yonenaga: Journal of Applied Physics, 1996, 80[12], 6991-6