Ag纳米颗粒等离激元光散射增强对Si刻蚀形貌的影响机制

通过实验与有限元(FDTD)模拟系统研究了不同粒径尺寸的Ag纳米颗粒在P(100)Si表面刻蚀过程中等离激元光散射增强对刻蚀孔形貌的影响。SEM结果表明,刻蚀孔由与粒径尺寸接近的垂直孔演化为一种上大下小的火炬状形貌特征孔,该孔的直径与纳米颗粒尺寸散射半径相仿。模拟不同粒径的Ag纳米颗粒进入刻蚀孔后的光散射特征,证实了Ag纳米颗粒等离激元散射对刻蚀孔初期形成的重要作用。分析表明,基于光照条件下电子-空穴的激发特征,刻蚀孔的形貌主要依赖Ag纳米颗粒等离激元散射的光增强,即通过改变入射光频率以及Ag纳米颗粒粒径可以有效地调控Si表面形貌特征。Ag纳米颗粒等离激元光散射增强技术在Si基太阳能电池、发光二极管(LED)器件等领域有潜在应用前景。

Effect of Ag Nanoparticles Plasmonic Scattering on the Morphology of Si Etching Holes

By Finite-Difference Time-Domain (FDTD) simulation and experiments, the effects of the plasmonic scattering of Ag nanoparticles with various diameters on morphology of Si etching holes was investigated during the etching process of P(100) Si. SEM results showed that the vertical hole evolves into a crater with large top and small bottom. The diameters of the holes are similar to the scattering radius of nanometer particle size. Light scattering characteristics of Ag nanoparticles with various sizes of Ag nanoparticles entering the etching hole are simulated, and the importance of plasmon scattering in the formation of the etched hole is confirmed. Based on the excitation characteristics of electron hole under illumination, the morphology of the etched hole mainly depends on the enhancement of scattering by Ag nanoparticles. That is to say, the surface morphology of Si can be effectively controlled by changing the incident light frequency and the size of Ag nanoparticles. Plasmonic scattering of Ag nanoparticles has potential applications in Si based solar cells, light-emitting diode (LED) devices and other fields.