Silicon-copper and silicon-zinc complexes in gallium phosphide

Diffusion of copper into silicon-doped gallium phosphide leads to electrical compensation for diffusion temperatures greater than or equal to 1123K and appreciable pairing of the two impurities occurs. The frequencies of the localized modes of Si(Ga)-Cu(Ga) defects are 453.8 and 484.2 cm -1 . Zinc diffusion at 1273K leads to the formation of Si(Ga)-Zn(Ga) pairs with vibrational frequencies of 458.0, 461.2 and 478.7 cm -1 . The results are compared with previous observations on the same donor-acceptor pair defects in gallium arsenide crystals.