Heavily Si-doped material was grown, by means of molecular beam epitaxy, using a single 69Ga source. Infra-red absorption methods were used to reveal the localized vibrational modes of Si complexes. It was found that the structure which was observed near to 367/cm was the same as that in the usual spectra for this material, and did not result from mixed Ga isotopes. The Si-X electron trap was associated with localized vibrational modes, at 368.4, 370.0 and 399.6/cm, which were typical of second-nearest neighbor donor-acceptor pairs. However, they were inconsistent with a suggested structure for a planar defect of the form, VGa-SiAs-AsGa. It was suggested that the defect was a perturbed SiGa-VGa center which involved a second Si atom or a second vacancy.

M.J.Ashwin, R.C.Newman, K.Muraki: Journal of Applied Physics, 1997, 82[1], 137-41