The effect of As interstitials and dislocations upon the lattice parameters of undoped semi-insulating single crystals was studied. It was shown that the dislocations in such crystals served as effective gettering sites for As interstitials, due to the deformation energy of the dislocations. The average excess As content in epilayers which had been grown by molecular-beam epitaxy at low temperatures was about 1%, and the lattice parameters of these epilayers were larger, than those of liquid-encapsulated Czochralski-grown material, by about 0.1%.

N.F.Chen, H.He, Y.Wang, L.Lin: Journal of Crystal Growth, 1997, 173, 325-9