ZnO(10(1)0)非极性表面的第一原理研究

采用基于密度泛函理论（DFT）的第一原理超级原胞模型计算了ZnO（10^-10）非极性表面的结构．计算表明顶层Zn原子明显向体内弛豫0．0328nm，第二层Zn原子的弛豫远离体材料0．0237nm，使得它类似于表面原子．顶层0原子的弛豫仅为0．0146nm，导致表面Zn-O二聚体有强烈扭转，扭转角达9．2°（10^-10）非极性表面Zn、O原子的电荷转移的计算表明这很可能就是（000±1）极性表面能稳定存在的原因．计算结果与其他理论计算结论和实验结论吻合很好．

First-principles Study of ZnO (10(1)0) Non-polar Surface

The structure of the ZnO(1010) non-polar surface is studied using first-principles slab calculations basedon density functional theory(DFT). It is found that the uppermost zinc atoms have a significant relaxation towardsthe bulk 0.032 8 nm, and the Zn atoms in the second layer show a significant relaxation away from the bulk 0.023 7nm, allowing them to appear as surface atoms. For oxygen atoms a small relaxation 0.014 6 nm is found, whichleads to a rotation angle 9.2°of the Zn-O dimer on the surface. The charge transfer of the Zn and O atoms of the(1010) non-polar surface are also calculated to prove that why the (000±1) polar surfaces are stable. Results in ex-cellent agreement with experiment have been obtained for the geometric and electric structures.