Joint International Research Laboratory of Information Display and Visualization, School of Electronic Science and Engineering, Southeast University, Nanjing, 210096, People's Republic of China.
Nanoscale. 2018 Aug 23;10(33):15468-15484. doi: 10.1039/c8nr02736f.
We report a multi-step synthetic method to obtain ultrathin silver nanowires (Ag NWs) from an aqueous solution with a ∼17 nm diameter average, and where some of them decreased down to 9 nm. Carefully designed seed screening processes including LED irradiation at high temperature for a short time, and then continuous H2O2 etching, and relative growth mechanisms of high-yield five-twinned pentagonal seeds and ultrathin Ag NWs in aqueous environment are detailed. Then, a rapid and simple multiphase interfacial assembly method particularly suitable for the separation of ultrathin Ag NWs from various by-products was demonstrated with a clear mechanism explanation. Next, a unique optical interaction between light and individual AG NWs, as well as feature structures in the AG NWs film, was investigated by a micro-domain optical confocal microscope measurement in situ together with a theoretical explanation using modal transmission theory. That revealed that the haze problem of AG NWs films was not only arising from the interaction between light and individual or crossed Ag NWs but was also greatly dependent on a weak coupling effect of leaky modes supported by adjacent Ag NWs with large distances which had not been considered before. We then provided direct experimental evidence and concluded how to obtain haze-free films with 100% transparency in the whole visible range based on ultrathin Ag NWs. This breakthrough in diameter confinement and purification of Ag NWs is a highly expected step to overcome the well-focused light diffusion and absorption problems of Ag NWs-based devices applied in various fields such as flexible electronics, high-clarity displays, visible transparent heaters, photovoltaics and various optoelectronic technologies.
我们报告了一种多步合成方法，可从水溶液中获得直径约为 17nm 的超薄银纳米线（AgNWs），其中一些纳米线直径减小到 9nm。详细设计了种子筛选过程，包括在高温下进行 LED 照射短时间，然后进行连续的 H2O2 刻蚀，以及在水相环境中高产五重孪晶五角形种子和超薄 AgNWs 的相对生长机制。然后，展示了一种快速简单的多相界面组装方法，特别是适合从各种副产物中分离超薄 AgNWs 的方法，并对其进行了清晰的机制解释。接下来，通过微域光学共焦显微镜原位测量和模态传输理论的理论解释，研究了光与单个 AgNW 之间的独特光学相互作用以及 AgNW 薄膜中的特征结构。这表明 AgNW 薄膜的雾度问题不仅源于光与单个或交叉 AgNW 的相互作用，而且还极大地取决于相邻 AgNW 之间的弱泄漏模式耦合效应，这是以前未考虑过的。然后，我们提供了直接的实验证据，并得出了如何基于超薄 AgNW 获得整个可见光范围内 100%透明度的无雾度薄膜的结论。这种在 AgNW 直径限制和纯化方面的突破，是克服基于 AgNW 的器件在柔性电子、高清晰度显示器、可见透明加热器、光伏和各种光电技术等各个领域中聚焦光扩散和吸收问题的高度期望的步骤。
