Zhao Huxian, Chen Xiaoshuang, Dong Ruibin, Lu Wei
National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Science, Shanghai 200083, People's Republic of China.
J Nanosci Nanotechnol. 2012 Jan;12(1):138-42. doi: 10.1166/jnn.2012.5129.
The stability and the optical band gap of the Zinc Oxide clusters (ZnO)n (n = 2-18) are investigated by using density functional theory (DFT) and the time-dependent density functional theory (TD-DFT), respectively. The differences between the HOMO-LUMO gap (delta(h-l)) and the optical gap (delta(opt)) are dramatic for small clusters (2 < or = n < or = 5). As the increasing of the cluster size, the differences become small. The results indicate that the stability and the optical gap are related to the sizes and symmetries of the clusters. Further, it is shown that the structures have much greater impact on the optical gap, there is the dipole-forbidden transition in the optical gap for high symmetric structures.
分别使用密度泛函理论（DFT）和含时密度泛函理论（TD-DFT）研究了氧化锌团簇(ZnO)n（n = 2 - 18）的稳定性和光学带隙。对于小团簇（2≤n≤5），最高占据分子轨道-最低未占据分子轨道能隙（δ(h-l)）和光学能隙（δ(opt)）之间的差异很大。随着团簇尺寸的增加，差异变小。结果表明，稳定性和光学能隙与团簇的尺寸和对称性有关。此外，结果表明结构对光学能隙有更大的影响，对于高对称结构，光学能隙中存在偶极禁戒跃迁。
