高温物质吸收特性调控技术

发布时间：2019-04-24 10:41

【摘要】：高温物质光谱吸收特性的调控在雷达探测、航空航天、生物医学、太阳能电池等方面都具有潜在的应用价值,利用表面等离子体效应调控金属材料光谱吸收特性越来越受到人们关注。目前对吸收特性调控技术的研究还局限在银、金等熔点相对较低的贵金属,在地壳中含量少,开采困难,应用范围具有一定的局限性。本论文为了满足高温环境的使用需求,提出了高温物质吸收特性调控技术的研究。表面等离子体是光照射在金属表面时,金属表面自由振荡的电子与光子相互作用而产生的一种电子倏逝波。本论文以表面等离子体效应为基础,运用时域有限差分法(FDTD),结合电磁场的相关理论,研究了两种基于超高温金属材料的周期纳米结构,通过改变不同的结构参数,对各种物理现象进行对比,发现吸收特性调控因子,并通过电磁场分布研究吸收机理。本论文的主要研究工作如下:构建基于金属钨的光栅型周期纳米结构,仿真分析其在波长200-4000nm范围内,结构周期、宽度、深度、抗氧化膜层厚度等不同参数对光谱吸收特性的影响。仿真分析表明,不同参数的吸收曲线光学特性存在异同,均会出现吸收峰,且吸收峰值达到93%以上;介电材料、周期、宽度、深度是影响吸收特性的主要因素,介电材料和周期对吸收峰的位置产生影响,随着参数的变化发生红移或蓝移。该研究结果为高温物质吸收特性的调控提供了新的方法。构建基于金属钽和介电材料Al2O3的圆柱型周期纳米阵列。保持其他结构参数不变,分别改变周期、圆柱半径、介电层材料,计算光谱吸收曲线,比较不同参数下吸收特性的异同,随着参数的改变,出现不同的物理现象,共振峰红移、蓝移、衰减、增强、带宽增大、减小等,变化规律不同。通过共振峰的电场分布图,分析两种不同的吸收机理,即金属表面等离子体激元共振和局域波导共振。该研究结果对于超高温金属纳米结构光谱吸收特性调控技术的研究具有指导作用。本论文的研究内容为亚波长金属周期阵列吸收特性的调控提供了新的调控因子,丰富了该类纳米结构的调控方法,便于人们根据实际应用中的需要对电磁波进行合适的操纵。
[Abstract]:The regulation of spectral absorption characteristics of high temperature substances has potential application value in radar detection, aerospace, biomedicine, solar cells and so on. More and more attention has been paid to the use of surface plasma effect to regulate the spectral absorption characteristics of metallic materials. At present, the study of absorption characteristics control technology is still limited in the relatively low melting point of silver, gold and other precious metals, the content in the earth's crust is less, mining is difficult, and the application scope has some limitations. In order to meet the demand of high temperature environment, the research of high temperature material absorption characteristics control technology was put forward in this paper. Surface plasma is an electron evanescent wave produced by the interaction of electrons and photons in the free oscillation of the metal surface when the light is emitted on the metal surface. In this paper, based on the surface plasma effect, two kinds of periodic nanostructures based on ultra-high temperature metal materials are studied by using the finite-difference time-domain (FDTD) (FDTD), combined with the theory of electromagnetic fields. Through the comparison of various physical phenomena, the regulatory factors of absorption characteristics were found, and the absorption mechanism was studied by the distribution of electromagnetic fields. The main work of this thesis is as follows: to construct the grating periodic nanostructure based on metal tungsten, and to simulate and analyze the structure period, width and depth in the wavelength range of 200-4000nm. The effect of different parameters such as the thickness of the antioxidation film on the spectral absorption characteristics. The simulation analysis shows that the optical properties of the absorption curves of different parameters are different, and the absorption peaks will appear, and the absorption peaks are over 93%. The dielectric material, period, width and depth are the main factors that affect the absorption characteristics. The dielectric material and the period affect the position of the absorption peak, and the red-shift or blue-shift occurs with the change of the parameters. The results of this study provide a new method for the regulation of absorption characteristics of high temperature substances. A cylindrical periodic nanoarray based on tantalum and dielectric material Al2O3 was constructed. Keep the other structural parameters unchanged, change the period, cylindrical radius, dielectric layer material, calculate the spectral absorption curve, compare the differences of absorption characteristics under different parameters, with the change of parameters, there are different physical phenomena, resonance peak red shift, Blue shift, attenuation, enhancement, bandwidth increase, decrease, and so on, the law of change is different. Two different absorption mechanisms, the plasmon resonance on the metal surface and the local waveguide resonance, are analyzed by means of the electric field distribution of the resonance peak. The results can be used to study the spectral absorption characteristics of ultra-high temperature metal nanostructures. The research contents of this paper provide a new regulation factor for the absorption characteristics of subwavelength metal periodic arrays, and enrich the regulation methods of this kind of nanostructures. It is convenient for people to properly manipulate electromagnetic waves according to the needs of practical applications.
【学位授予单位】：中北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG111;TB383.1

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