Recently, bilayer ZnO films grown on Cu, Ag, and Au supports have been reported as new materials with potentially interesting properties. In this work we have investigated the structure and stability of small Au_n clusters (n = 2, 3, 4) and of a larger gold aggregate, Au₂₀, deposited on ZnO/Cu(111) ultrathin films using a spin-polarized DFT+U/D2′ approach which includes dispersion corrections. The properties of Au clusters on ZnO/Cu(111) are completely different from those of the corresponding gas-phase units, but also from the same Au clusters deposited on an unsupported ZnO bilayer. On ZnO/Cu(111) small Au_n clusters (n = 3, 4) are linear and Au₂₀ is two-dimensional (2D), at variance with the free counterparts. The stability of Au clusters on ZnO/Cu(111) is governed by a spontaneous charge transfer from the underlying Cu(111) substrate via electron tunneling through the thin ZnO film, resulting in negatively charged Au clusters. A Bader charge analysis shows that the excess electrons are localized on the edges of the Au clusters to minimize Coulomb interactions.

中文翻译：

---

ZnO / Cu（111）双层膜上金簇阴离子的自发形成

近来，已经报道了在Cu，Ag和Au载体上生长的双层ZnO膜是具有潜在有趣性质的新材料。在这项工作中，我们研究了使用自旋极化DFT沉积在ZnO / Cu（111）超薄膜上的小Au _n团簇（n = 2、3、4）和较大的金团聚体Au ₂₀的结构和稳定性。+ U / D2'方法，包括色散校正。ZnO / Cu（111）上的Au团簇的性质与相应的气相单元的性质完全不同，但也与沉积在未支撑的ZnO双层上的相同Au团簇的性质完全不同。在ZnO / Cu（111）上，小的Au _n团簇（n = 3，4）是线性的，Au ₂₀是二维（2D），与自由副本有差异。ZnO / Cu（111）上Au团簇的稳定性受自下层Cu（111）衬底通过电子隧穿穿过ZnO薄膜的自发电荷转移控制，从而导致带负电荷的Au团簇。Bader电荷分析表明，多余的电子位于Au簇的边缘，以最大程度地减小库仑相互作用。