Complexes of group-VI donors with hydrogen in GaP

Local vibrational modes due to complexes of hydrogen with sulfur, selenium and tellurium in gallium phosphide are reported together with the correspon ding mode due to the deuterium-sulfur complex. The wave numbers of these mo des indicate that hydrogen or deuterium binds to one of the host phosphorus atoms which are next-nearest neighbors of the group-VI donor. Experiments under uniaxial stress show that the complexes have C-s (C-1h) symmetry, the mirror planes being {110} planes. The orientation of the mode-induced elec tric dipole moment is determined for each of the complexes. The structure o f the complexes of group-VI donors with hydrogen in GaP is different from t he one determined previously in other III-V compounds such as GaAs or AlSb. (C) 1999 Elsevier Science B.V. All rights reserved.