为了应对能源枯竭和环境污染这一关乎人类生存的重要问题,太阳能电池是利用太阳能这一低廉并且对环境友好的清洁能源的有效手段。但是光伏器件易受灰尘、粉尘等固体微颗粒污染物的影响,从而大大减少光电转化效率,因此在光伏器件表面引...为了应对能源枯竭和环境污染这一关乎人类生存的重要问题,太阳能电池是利用太阳能这一低廉并且对环境友好的清洁能源的有效手段。但是光伏器件易受灰尘、粉尘等固体微颗粒污染物的影响,从而大大减少光电转化效率,因此在光伏器件表面引入超疏水自清洁薄膜则成为一种潜在有效的清洁手段。基于前人研究并参考“荷叶表面微观结构”,提出了一种具有高透光的SiO2微孔膜耦合ZnO纳米棒的分级自清洁结构,通过FDTD方法对设计的薄膜结构进行相应的数值模拟,得到了三组透过率、反射率和吸收率等数据曲线,以及膜结构内部不同截面的电场分布。从模拟结果来看,该膜结构在微纳分级复合结构保证超疏水性的同时,具有优异的光学性能和极强的推广可行性。To address the critical issue of energy depletion and environmental pollution that threatens human survival, solar cells represent an effective means of harnessing solar energy, a low-cost and environmentally friendly clean energy source. However, photovoltaic devices are susceptible to the influence of solid particulate pollutants such as dust and powder, which can significantly reduce their photoelectric conversion efficiency. Therefore, introducing a superhydrophobic self-cleaning film on the surface of solar panels has become a potentially effective cleaning solution. Based on previous research and inspired by the microstructure of lotus leaf surfaces, we propose a hierarchical self-cleaning structure composed of a highly transparent silica microporous film coupled with zinc oxide nanorods. The designed film structure was numerically simulated using the FDTD method, yielding three sets of data curves for transmittance, reflectance, and absorptance, as well as the electric field distribution at different cross-sections within the film structure. The simulation results indicate that the film structure maintains super-hydrophobicity through its micro-nano hierarchical composite structure while exhibiting excellent optical properties and strong feasibility for widespread application.展开更多
复杂形状的纳米星一直是认识等离子体现象的主要障碍。本文通过时域有限差分(FDTD)方法,对纳米星形结构进行模拟分析。我们对不同几何参数(如粒子直径、金星分支尖角的粗细和金星分支的数量)下的光谱响应进行了数值研究,以阐明纳米星的...复杂形状的纳米星一直是认识等离子体现象的主要障碍。本文通过时域有限差分(FDTD)方法,对纳米星形结构进行模拟分析。我们对不同几何参数(如粒子直径、金星分支尖角的粗细和金星分支的数量)下的光谱响应进行了数值研究,以阐明纳米星的光学特性与几何结构之间的关系。另外,还在金纳米星的基础上耦合了银,发现可以通过调整银的不同含量来调谐纳米星的消光峰,而且能提升纳米粒子的电场增强。我们的结果为确定选择不同激发波长的SERS应用中纳米星的几何形状提供了理论指导。这项工作为开发具有宽吸收光谱增强电磁场的等离子金属晶体结构铺平了道路。此外,这项研究还为医学成像和农药残留检测提供了一种有效的SERS基底。The complex shape of nanostars has been a major obstacle to understanding plasma phenomena. In this paper, the finite difference Time domain (FDTD) method is used to simulate and analyze the nanostar structure. Numerical studies of spectral responses under different geometric parameters such as particle diameter, the thickness of Venusian branches, and the number of Venusian branches are carried out to clarify the relationship between the optical properties of nanostars and their geometric structure. In addition, silver is coupled to the gold nanostars, and it is found that the extinction peak of the nanostars can be tuned by adjusting the different content of silver, and the electric field enhancement of the nanoparticles can be improved. Our results provide theoretical guidance for determining the geometry of nanostars in SERS applications where different excitation wavelengths are selected. This work paves the way for the development of plasma metallic structures with a wide absorption spectrum enhanced electromagnetic field. In addition, this study provides an effective SERS substrate for medical imaging and pesticide residue detection.展开更多
文摘提出一种新的节省计算空间的FDTD-PWS混合算法,并应用于透镜天线的焦面场分析.首先采用FDTD(Finite-Difference Time-Domain)求解得到聚焦透镜天线的口面场的幅度和相位分布,再通过PWS(Plane Wave Spectrum)外推至焦平面,求解得出焦面场分布.根据天线场分布的对称性,将PEC(Perfect Electric Conductor)和PMC(Perfect Magnetic Conduc-tor)边界应用于FDTD的仿真过程,使仿真模型缩减为原模型的1/4,进一步节省了计算空间.应用于毫米波聚焦透镜天线的焦面场仿真分析,并对其焦面场进行平面近场扫描测试,将仿真结果进行探头补偿后与实验数据作比较,证明该方法是精确和高效的.
文摘为了应对能源枯竭和环境污染这一关乎人类生存的重要问题,太阳能电池是利用太阳能这一低廉并且对环境友好的清洁能源的有效手段。但是光伏器件易受灰尘、粉尘等固体微颗粒污染物的影响,从而大大减少光电转化效率,因此在光伏器件表面引入超疏水自清洁薄膜则成为一种潜在有效的清洁手段。基于前人研究并参考“荷叶表面微观结构”,提出了一种具有高透光的SiO2微孔膜耦合ZnO纳米棒的分级自清洁结构,通过FDTD方法对设计的薄膜结构进行相应的数值模拟,得到了三组透过率、反射率和吸收率等数据曲线,以及膜结构内部不同截面的电场分布。从模拟结果来看,该膜结构在微纳分级复合结构保证超疏水性的同时,具有优异的光学性能和极强的推广可行性。To address the critical issue of energy depletion and environmental pollution that threatens human survival, solar cells represent an effective means of harnessing solar energy, a low-cost and environmentally friendly clean energy source. However, photovoltaic devices are susceptible to the influence of solid particulate pollutants such as dust and powder, which can significantly reduce their photoelectric conversion efficiency. Therefore, introducing a superhydrophobic self-cleaning film on the surface of solar panels has become a potentially effective cleaning solution. Based on previous research and inspired by the microstructure of lotus leaf surfaces, we propose a hierarchical self-cleaning structure composed of a highly transparent silica microporous film coupled with zinc oxide nanorods. The designed film structure was numerically simulated using the FDTD method, yielding three sets of data curves for transmittance, reflectance, and absorptance, as well as the electric field distribution at different cross-sections within the film structure. The simulation results indicate that the film structure maintains super-hydrophobicity through its micro-nano hierarchical composite structure while exhibiting excellent optical properties and strong feasibility for widespread application.
文摘复杂形状的纳米星一直是认识等离子体现象的主要障碍。本文通过时域有限差分(FDTD)方法,对纳米星形结构进行模拟分析。我们对不同几何参数(如粒子直径、金星分支尖角的粗细和金星分支的数量)下的光谱响应进行了数值研究,以阐明纳米星的光学特性与几何结构之间的关系。另外,还在金纳米星的基础上耦合了银,发现可以通过调整银的不同含量来调谐纳米星的消光峰,而且能提升纳米粒子的电场增强。我们的结果为确定选择不同激发波长的SERS应用中纳米星的几何形状提供了理论指导。这项工作为开发具有宽吸收光谱增强电磁场的等离子金属晶体结构铺平了道路。此外,这项研究还为医学成像和农药残留检测提供了一种有效的SERS基底。The complex shape of nanostars has been a major obstacle to understanding plasma phenomena. In this paper, the finite difference Time domain (FDTD) method is used to simulate and analyze the nanostar structure. Numerical studies of spectral responses under different geometric parameters such as particle diameter, the thickness of Venusian branches, and the number of Venusian branches are carried out to clarify the relationship between the optical properties of nanostars and their geometric structure. In addition, silver is coupled to the gold nanostars, and it is found that the extinction peak of the nanostars can be tuned by adjusting the different content of silver, and the electric field enhancement of the nanoparticles can be improved. Our results provide theoretical guidance for determining the geometry of nanostars in SERS applications where different excitation wavelengths are selected. This work paves the way for the development of plasma metallic structures with a wide absorption spectrum enhanced electromagnetic field. In addition, this study provides an effective SERS substrate for medical imaging and pesticide residue detection.
