In LEC-grown samples, with an O content greater than 1015/cm3, two sharp vibrational absorption lines were found at 3108.0 and 3235.0/cm. These lines were attributed to the stretching modes of H bonded to interstitial O in 2 different centers, (Oi-H)I and (Oi-H)II, as proved by the detection of isotopically shifted lines in material which was also doped with D. The center, (Oi-H)I, was a single H atom bonded to O and was photo-sensitive below 100K. The (Oi-H)II was a di-hydrogen center with the two H atoms on equivalent positions around O.

Vibrational Absorption of Hydrogen Bonded to Interstitial Oxygen in GaAs and GaP. W.Ulrici, M.Jurisch: Physica Status Solidi B, 2002, 233[2], 263-9