Photonic Crystals for Enhancing Thermophotovoltaic Energy Conversion

Abstract

Thermophotovoltaics (TPV) converts the radiant energy of a thermal source into electrical energy using photovoltaic cells. TPV has a number of attractive features, including: fuel versatility (nuclear, fossil, solar, etc.), quiet operation, low maintenance, low emissions, light weight, high power density, modularity, and possibility for cogeneration of heat and electricity. Some of these features are highly attractive for military applications (Navy and Army). TPV could also be used for distributed power and automotive applications wherever fuel cells, microturbines, or cogeneration are presently being considered if the efficiencies could be raised to around 30%.This proposal primarily examine approaches to improving the radiative efficiency. The ideal irradiance for the PV cell is monochromatic illumination at the bandgap. The photonic crystal approach allows for the tailoring of thermal emission spectral bandwidth 4 at specific wavelengths of interest. The experimental realization of metallic photonic crystal structures, the optical transmission, reflection and absorption characterization of it have all been carried out in detail and will be presented next. Additionally, comprehensive models of TPV conversion has been developed and applied to the metallic photonic crystal system.

Flexible Transparent Metal/Polymer Composite Materials Based on Optical Resonant Laminate Structures

“…In this contribution, we establish “design criteria” for the fabrication of optically resonant polymer/metal laminate structures and we demonstrate the fabrication of metal/polymer composite materials with 5-fold increase of optical transparency (as compared to the respective monolithic structures) that retain the mechanical flexibility and robustness that is characteristic of polymer materials. The excellent electron conductivity of laminated polymer/metal hybrid structures that is imparted by the continuous metal component could render the resulting “transparent metallodielectric nanocomposites” a platform for innovative material technologies in areas such as plastic electronics, power limiting, or thermo-photovoltaics for energy-recycling. − The structure of this article is as follows: First, we provide a brief review of the optical properties of 1D-periodic metallodielectric structures and establish the design parameters for optical resonant polymer/metal composite structures. Subsequently the fabrication of near-transparent polystyrene/gold laminate structures will be demonstrated and the optical properties evaluated against model calculations.…”