A H-related defect labelled as H-I*, observed in as-grown hydrothermal ZnO, was studied by means of infra-red absorption spectroscopy. The defect possessed a stretch local vibrational mode, at 3577.3/cm, that was associated with a single H atom bound to O; with the O-H bond oriented along the c-axis of the crystal. The H-I* could be destroyed only after annealing for several hours at 1200C.

Dominant Hydrogen-Oxygen Complex in Hydrothermally Grown ZnO. Lavrov, E.V., Börrnert, F., Weber, J.: Physical Review B, 2005, 71[3], 035205