ELECTRON-NUCLEAR DOUBLE-RESONANCE OF CHALCOGEN DONORS IN GAP REVISITED

Using electron nuclear double resonance (ENDOR) of GaP crystals contai ning shallow S donors it was shown that the ENDOR spectra previously d etected optically in the two infrared photoluminescence bands assigned to oxygen in oxygen-doped GaP are indeed due to S donors which must h ave been present simultaneously in those crystals. Furthermore it is s hown that the results of the published ENDOR investigations of both S and Te donors in GaP must be revised, Finally the measured ligand hype rfine interaction of S and Te donors are discussed within the frame of effective mass theory.