The stability of polar oxide surfaces: The interaction of H2O with ZnO(0001) and ZnO(000(1)over-bar

Recently, a new mechanism for the stabilization of the polar surfaces of Zn O has been proposed. This mechanism involves the transfer of electrons betw een the (0001) and (000 (1) over bar) surface. In the current study an alte rnative mechanism involving the adsorption of water onto the polar surfaces has been investigated using ab initio all electron, hybrid density-functio nal theory. On the basis of the current study, such a stabilization mechani sm can be ruled out at low-temperatures and low-partial pressure of water. In addition, we present evidence that the ZnO(000 (1) over bar)-O surface m ay be a gas sensor for hydrogen. (C) 2001 American Institute of Physics.