Nobel metal nanostructures, such as silver nanowires (AgNWs), have attracted considerable attention due to their extraordinary capability to manipulate light-matter interactions at the nanoscale and promising applications in various areas. However, the underlying mechanism of photoluminescence (PL) emission of AgNWs on a metal film (NWoF structure) is still under debate. Here, we provided an exhaustive investigation of the PL behaviors of AgNWs by performing substrate-dependent PL imaging, as well as power-dependent PL spectra and photoblinking dynamics of single AgNWs on an Ag film with Al₂O₃ as a dielectric space. The similar PL spectra among suspension AgNWs, crossed AgNWs on Si/SiO₂ substrate, and single AgNWs on the Ag films confirmed that PL emission from NWoF structures is originated from AgNWs, rather than Ag films. Three PL peaks from AgNWs on the Ag film have been attributed to the photoactive Ag nanoclusters, the radiative recombination of intraband transitions, and the possible gap plasmonic modes, respectively, which have been evidenced by analysis of power-dependent PL spectra and photoblinking dynamics. These findings may provide new insight into the PL mechanisms of AgNWs and offer inspiration to develop customized plasmonic applications.

中文翻译：

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Ag 薄膜上 Ag 纳米线的功率依赖性混合光致发光发射


诺贝尔金属纳米结构，如银纳米线 （AgNW），因其在纳米尺度上操纵光-物质相互作用的非凡能力以及在各个领域的应用前景广阔而引起了相当大的关注。然而，AgNW 在金属薄膜（NWoF 结构）上光致发光 （PL） 的潜在机制仍在争论中。在这里，我们通过执行衬底依赖性 PL 成像，以及以 Al₂O₃ 为介电空间的 Ag 薄膜上单个 AgNWs 的功率依赖性 PL 光谱和光闪烁动力学，对 AgNWs 的 PL 行为进行了详尽的研究。悬浮 AgNWs、Si/SiO₂ 衬底上的交叉 AgNWs 和 Ag 薄膜上的单个 AgNWs 之间的相似 PL 光谱证实了 NWoF 结构的 PL 发射来源于 AgNWs，而不是 Ag 薄膜。Ag 薄膜上 AgNW 的三个 PL 峰分别归因于光活性 Ag 纳米团簇、带内跃迁的辐射复合和可能的间隙等离子体模式，这已经通过分析功率依赖性 PL 光谱和光闪烁动力学得到了证明。这些发现可能为 AgNWs 的 PL 机制提供新的见解，并为开发定制的等离子体应用提供灵感。