对称微纳米结构的光致热效应增强研究

发布时间：2018-05-24 23:11

本文选题：微纳米结构 + 局域表面等离子激元共振　；参考：《贵州大学》2015年硕士论文

【摘要】：微纳米结构因其表面效应、量子尺寸效应、小尺寸效应等在化学、力学、光学、热学等方面的性能与众不同。贵金属纳米结构作为微纳米结构的一个典型代表,因其独特的表面等离激元共振(localized surface plasmon resonance,LSPR)特性,对光具有强吸收能力,引起的光致热效应吸引了广大研究者的兴趣,适当的金属纳米结构可以作为高效的光致纳米热源,将电磁场高度集中于纳米尺度的体积内,易实现在纳米尺度上对热的操控,在化学催化、热辅助磁记录、生物医疗等方面有着潜在的应用价值。本文结合离散偶极近似方法与傅里叶热传导定律,分析了几种金属纳米结构近区的电磁场分布,并计算出结构本身及周围水介质环境的温度分布,直观的从数值上体现出该结构的光致热效应增强现象。通过对一维对称性破缺金纳米结构及其对称性改变后的光学性质与温度分布的模拟分析可得出,金属纳米结构对称性的改变,将影响结构近区的磁场分布,导致温度发生变化,并在较大的近红外波段实现对光的选择性吸收,在纳米尺度上对热的调控;进一步的研究表明,一维对称性破缺金纳米结构组成的对称系统的光学性质依赖于结构间的间距,在不同偏振方向的入射光激励下,其等离子激元吸收峰随着间距的减小发生相应的红移或蓝移。此外,通过改变对称H型金纳米结构偏振方向可以在较大的温差范围内调控温度。此研究可以为纳米尺度下精确控制光致热效应的温度和设计热等离子纳米器件等提供参考。
[Abstract]:Because of its surface effect, quantum size effect and small size effect, the microstructures have different properties in chemistry, mechanics, optics, heat and so on. Noble metal nanostructures, as a typical representative of microstructures, have strong absorption ability to light due to their unique surface isoexciton resonance surface plasmon resonance and LSPRs. The photothermal effect of noble metal nanostructures has attracted the interest of many researchers. Appropriate metal nanostructures can be used as high efficient photoinduced nano-heat sources, electromagnetic fields are highly concentrated in nanoscale volume, thermal manipulation on nanoscale, chemical catalysis, thermally assisted magnetic recording can be realized easily. Biomedicine has potential application value. Based on the discrete dipole approximation method and Fourier's heat conduction law, the electromagnetic field distribution in the near region of several metal nanostructures is analyzed, and the temperature distribution of the structure itself and the surrounding water medium environment is calculated. The enhancement of photothermal effect of the structure can be seen numerically. Through the simulation and analysis of the optical properties and temperature distribution of the one-dimensional symmetry broken gold nanostructures and their symmetry changes, it can be concluded that the changes of the symmetry of the metal nanostructures will affect the magnetic field distribution in the near region of the structure and lead to the temperature change. The optical properties of the symmetry system composed of one-dimensional symmetry breaking gold nanostructures depend on the spacing between the structures, and the optical properties of the one-dimensional symmetry breaking gold nanostructures depend on the distance between the structures, and the optical properties of the symmetry system are controlled at the nanoscale scale, and the optical properties of the one-dimensional symmetry breaking gold nanostructures depend on the distance between the structures. Under the excitation of the incident light with different polarization directions, the absorption peaks of plasma exciters shift red or blue with the decrease of the distance. In addition, the temperature can be adjusted in a large temperature range by changing the polarization direction of the symmetrical H-type gold nanostructures. This study can be used as a reference for accurately controlling the temperature of photothermal effect and designing thermal plasma nanodevices at nanometer scale.
【学位授予单位】：贵州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1

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