Surface Plasma Focus Modulation And Improvement Of Solar Cell Absorption Study

Metal surface plasmon forms the major part of the fascinating field of nanophotonics, at metallic interfaces or in metallic nanostructures, which has the ability to confine electromagnetic fields under dimensions on the order of or smaller than the wavelength, leading to an enhanced optical near field. Surface plasmon polaritons (SPPs) and localized surface plasmon (LSP) are two dividual ingredients belong to plasmon. Theoretically, to utilize the long propagation characteristic of SPPs, it is possible to develop many sub-wavelength dimension photonic devices; and make use of the LSP to exploit metal nanostructures to block radiation for sub-wavelength area electromagnetic energy's confinement. Base on this two special properties, this thesis carry out two kind of application research:1. First of all, to investigate the possibility of far-field superfocusing, this thesis analyzes a plasmonic lens model, which is a metal film structure constituted with nano-pinholes; and then have make a study of the focus modulation property of this kind of plasmonic Lens. Finite-difference and time-domain (FDTD) method is used to analyze the focal properties. Numerical analysis results demonstrate that, on the one hand, this flat film structure indeed can realize enhanced focusing; on the another hand, Varying thickness of Ag film may receive different focusing effect; the lens's focus shift to the far-field from near-field slowly with a increase in Ag film thickness; the size of focus in near-field is small than one wavelength, but in the far-field is slightly larger.2. In order to improve the thin film photoelectric conversion efficiency of solar cells, this paper examines a metal nanoparticles embedded composite solar cell materials. With the help of three dimensional electromagnetic simulation software, the metal-organic hybrid thin films structure was established in the thesis; and then, by means of simulation, there are comparative analyses of metal particles on the solar cell efficiency of photon absorption. The calculation data show that, metal nanoparticles can play an enhanced role of photon absorption due to the LSP resonance effect; in the organic material, changing the location, size, shape, and array period, the electromagnetic field distribution will be changed, and then the enhanced photon absorption effects are different. Finally, through a series of comparative analysis, the thesis summarizes an optimal array layout of metal nanoparticles, providing a pretty good foundation for the design of hybrid organic thin-film solar cells.