Dominant hydrogen-oxygen complex in hydrothermally grown ZnO

A hydrogen-related defect labeled as H-I*, observed in as-grown hydrothermal ZnO, is studied by means of infrared absorption spectroscopy. The defect possesses a stretch local vibrational mode at 3577.3 cm(-1) that is associated with a single hydrogen atom bound to oxygen with the O-H bond oriented along the c axis of the crystal. H-I* can be destroyed only after anneal for several hours at 1200 degreesC. Possible microscopic models of H-I* are discussed.