Understanding the Thermal Stability of Silver Nanoparticles Embedded in a-Si
Understanding the Thermal Stability of Silver Nanoparticles Embedded in a-Si
复制标题
DOI：
10.1021/acs.jpcc.5b07324
复制
发表时间：
2015-10-15
影响因子：
3.7
通讯作者：
Di Vece, Marcel
中科院分区：
文献类型：
--
作者：
Gould, Anna L.;Kadkhodazadeh, Shima;Di Vece, Marcel
在硅中包含银等离子体纳米颗粒对于光致发光是高度相关的，因为它可以增强光吸收。我们报告了这种原始银纳米粒子嵌入在a-Si热处理后的稳定性的调查。我们通过原位和异位高分辨率和高角度环形暗场扫描透射电子显微镜（HRTEM和HAADF STEM）研究了形态学变化。Ag颗粒的熔化和随后的Ag和Si原子的相互扩散与Ag纳米颗粒的尺寸以及表面缺陷的存在密切相关。在无定形硅框架中形成部分空隙，其中发现部分Ag纳米颗粒由于几何不稳定性而优先扩散。使用系综分子动力学的计算模拟证实了实验结果：非晶Si环境的结构特性是重要的，以及不完整的银纳米颗粒表面的包装。这些因素影响熔化温度，导致Ag纳米颗粒的某些部分优先溶解，而其他区域在高温下保持稳定。
The inclusion of silver plasmonic nanoparticles in silicon is highly relevant for photovoltaics as it may enhance optical absorption. We report an investigation of the stability of such pristine silver nanoparticles embedded in a-Si upon heat treatment. We have investigated the morphological changes via in situ and ex situ high-resolution and high-angle annular dark-field scanning transmission electron microscopy (HRTEM and HAADF STEM). The melting of Ag particles and subsequent interdiffusion of Ag and Si atoms are strongly related to the size of the Ag nanoparticles, as well as the presence of surface imperfections. Partial voids in the amorphous-Si framework are formed where sections of the Ag nanoparticles are found preferentially to diffuse away due to geometric instability. Computational simulations using ensemble molecular dynamics confirm the experimental results: the structural properties of the amorphous-Si environment are important as well as incomplete packing of the Ag nanoparticle surfaces. These factors affect the melting temperature, causing some parts of the Ag nanoparticles to dissolve preferentially and other areas to remain stable at high temperatures.