Méndez-Reyes José M, Monroy B Marel, Bizarro Monserrat, Güell Frank, Martínez Ana, Ramos Estrella
Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México. Circuito Interior, S N. Ciudad Universitaria, P.O. Box 70-360, Coyoacán, 04510, México DF, Mexico.
Phys Chem Chem Phys. 2015 Sep 7;17(33):21525-32. doi: 10.1039/c5cp01415h. Epub 2015 Jul 29.
Several techniques for obtaining ZnO nanowires (ZnO NWs) have been reported in the literature. In particular, vapour-liquid-solid (VLS) with Au as a catalyst is widely used. During this process, Au impurities in the ZnO NWs can be incorporated accidentally, and for this reason we named these impurities as intruders. It is thought that these intruders may produce interesting alterations in the electronic characteristics of nanowires. In the experiment, it is not easy to detect either Au atoms in these nanowires, or the modification that intruders produce in different electrical, optical and other properties. For this reason, in this density functional theory investigation, the effect of Au intruders on ZnO NWs is analysed. Au extended (thread) and point defects (atoms replacing Zn or O, or Au interstitials) are used to simulate the presence of gold atoms. Optimised geometries, band-gaps and density of states indicate that the presence of small amounts of Au drastically modifies the electronic states of ZnO NWs. The results reported here clearly indicate that small amounts of Au have a strong impact on the electronic properties of ZnO NWs, introducing states in the band edges that may promote transitions in the visible spectral region. The presence of Au as an intruder in ZnO NWs enhances the potential use of this system for photonic and photovoltaic applications.
文献中已报道了几种制备氧化锌纳米线（ZnO NWs）的技术。特别是，以金作为催化剂的气-液-固（VLS）法被广泛使用。在此过程中，氧化锌纳米线中的金杂质可能会意外掺入，因此我们将这些杂质称为入侵者。据认为，这些入侵者可能会使纳米线的电子特性产生有趣的变化。在实验中，检测这些纳米线中的金原子或入侵者对不同电学、光学及其他性质产生的改变并不容易。因此，在这项密度泛函理论研究中，分析了金入侵者对氧化锌纳米线的影响。使用金扩展（线状）和点缺陷（取代锌或氧的原子，或金间隙原子）来模拟金原子的存在。优化的几何结构、带隙和态密度表明，少量金的存在会极大地改变氧化锌纳米线的电子态。此处报道的结果清楚地表明，少量金对氧化锌纳米线的电子性质有强烈影响，在带边引入了可能促进可见光谱区域跃迁的态。金作为入侵者存在于氧化锌纳米线中增强了该系统在光子学和光伏应用方面的潜在用途。
