Abstract
We employ hybrid density functional calculations to analyze the structure and stability of the (101¯0) and (112¯0) ZnO surfaces, confirming the relative stability of the two surfaces. We then examine morphological features, including steps, dimer vacancies, and grooves, at the main nonpolar ZnO surface using density functional methods. Calculations explain why steps are common on the (101¯0) surface even at room temperature, as seen in experiment. The surface structure established has been used to obtain the definitive ionization potential and electron affinity of ZnO in good agreement with experiment. The band bending across the surface is analyzed by the decomposition of the density of states for each atomic layer. The upward surface band bending at the (101¯0) surface affects mostly the valence band by 0.32 eV, which results in the surface band gap closing by 0.31 eV; at the (112¯0) surface, the valence band remains flat and the conduction band bends up by 0.18 eV opening the surface band gap by 0.12 eV.
Original language | English |
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Pages (from-to) | 11598-11611 |
Number of pages | 14 |
Journal | Journal of Physical Chemistry C |
Volume | 119 |
Issue number | 21 |
DOIs | |
Publication status | Published - 28 May 2015 |
Bibliographical note
Publisher Copyright:© 2015 American Chemical Society.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- General Energy
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films