Abstract
We have calculated the stability of two of the low-index surfaces known to dominate the morphology of ZnO as a function of stoichiometry. These two surfaces are (101̄0) and (112̄0). In each case, two terminations only are stable for a significant range of oxygen and hydrogen chemical potential: the pure stoichiometric surface and a surface covered in a monolayer of water. The mode by which the water adsorbs is however different for the two surfaces considered. On the (101̄0) surface the close proximity of the water molecules means hydrogen bonding can occur between adjacent chemiabsorbed water molecules and hence there is little difference in the stability of the hydrated and hydroxylated surface, and in fact the most stable surface occurs with a combination of dissociated and undissociated water adsorption. In the case of the (112̄0) surface, it is only when full dissociation has occurred that a hydrogen-bonding network can form. Our results also show good agreement between DFT and atomistic simulations, suggesting that potential based methods can usefully be applied to ZnO.
Original language | English |
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Pages (from-to) | 7985-7991 |
Number of pages | 7 |
Journal | Journal of Physical Chemistry B |
Volume | 110 |
Issue number | 15 |
Early online date | 29 Mar 2006 |
DOIs | |
Publication status | Published - 1 Apr 2006 |
Externally published | Yes |