Self-Assembled Binary Photonic Crystals under the Active Confinement and Their Light Trapping
Self-Assembled Binary Photonic Crystals under the Active Confinement and Their Light Trapping
复制标题
主动约束下的自组装二元光子晶体及其光捕获
DOI：
10.1021/acs.langmuir.9b03945
复制
发表时间：
2020
期刊：
影响因子：
3.9
通讯作者：
Ma Yu-Qiang
中科院分区：
文献类型：
--
作者：
Huang Tian-Chen;Zhou Xing-Ping;Ren Chun-Lai;Zhan Peng;Ma Yu-Qiang
本文首次提出了在主动约束下，利用带相反电荷的胶体椭球和球的自组装来实现远距离有序光子晶体。与传统的被动约束相比，主动约束的一个特点是边界是可移动的。我们的布朗动力学模拟表明，当两个边界周期性振荡时，在强约束下可以获得类似准二维胶体晶体的动态稳定结构。平面内结构可以通过改变两种粒子的电荷比来调节。这些动态稳定的结构是由最小的静电能和限制粒子的增加迁移率决定的，这在平衡状态下是不可用的。数值模拟结果表明，该介电二元光子板可以完全约束光而不产生任何辐射，符合具有发散寿命和超尖锐光谱轮廓的典型光束缚态。考虑到光子板的可变几何形状，捕获光场可能适用于增强光-物质相互作用。此外，对于较厚的层，在主动约束的驱动下，逐层有序结构自发发生，而在被动约束中没有全局有序结构。结果表明，边界运动可以成为影响自组装结构和功能的重要因素。
The self-assembly of oppositely charged colloidal ellipsoids and spheres under active confinement is first proposed to achieve long-range ordered photonic crystals. Compared with the conventional passive confinement, a characteristic of the active confinement is that boundaries are movable. Our Brownian dynamics simulations show that dynamic steady structures, similar to quasi-2D colloidal crystals, can be obtained under the strong confinement when the two boundaries periodically oscillate together. The in-plane structures can be regulated by changing the charge ratio of the two kinds of particles. These dynamic steady structures are determined by the minimum electrostatic energy with the aid of increased mobility of confined particles, which are not available in equilibrium. Numerical simulations verify that light can be perfectly confined in this dielectric binary photonic slab without any radiation, which corresponds to a typical optical bound state with divergent lifetime and ultrasharp spectral profile. Given the changeable geometry of this photonic slab, the trapped optical field might be applicable to enhanced light–matter interactions. In addition, for thicker layers, layer-by-layer ordered structures occur spontaneously, driven by the active confinement, while no global order occurs in the passive confinement. Our results show that the boundary motion can become an important factor affecting self-assembled structure and function.