Adsorption of atomic hydrogen on ZnO(1010): STM study

The adsorption of atomic hydrogen on a single crystal ZnO(10 (1) over bar0) surface has been studied by scanning tunneling microscopy (STM) under ultrahigh vacuum conditions at room temperature and at elevated temperatures. High resolution STM images indicate that a well-ordered (1 x 1) H adlayer is formed on the ZnO(10 (1) over bar0) surface. The STM data strongly indicate that the hydrogen adsorbs on top of the oxygen atoms forming hydroxyl species. Scanning tunneling spectroscopy (STS) studies reveal a H atom induced metallization at room temperature. In contrast to the clean surface for the hydrogen-covered surface distinct defects structures consisting of missing O and Zn atoms could be identified.