Three-dimensional metallic architectures for photonic and energy storage applications
Materials exhibiting multi–dimensional structure with characteristic feature sizes ranging from the nanometer scale to the micrometer scale have extraordinary potential for emerging applications that cannot be achieved using simple, non–structured materials. Much work in the area has focused on the use of dielectric or polymeric materials, however, three-dimensional (3D) metallic materials are far less studied and especially interesting for photonic and energy storage applications. Sacrificial templates are commonly used for the fabrication of materials possessing 3D structure. Self-assembly is particularly attractive for applications demanding large-area templates at low cost. This work focused on the incorporation of metallic materials into 3D templates, especially those fabricated by self-assembly, for solar energy harvesting, chiral metamaterial, and energy storage applications. 3D metallic architectures are useful for solar thermophotovotlaics (sTPV). This technology seeks to overcome losses in solar energy harvesting due to the broad spectral distribution of energies emitted by the sun. Single junction photovoltaic (PV) cells efficiently convert solar radiation to electricity in a narrowed range of energies concentrated around the energy of the PV cell electronic band gap. A sTPV device uses an intermediate component, placed between the sun and the PV cell that spectrally concentrates solar radiation to coincide with the PV cell electronic band gap. A large part of this thesis is devoted to the development of 3D photonic crystals, fabricated using selfassembled templates, which selectively emit thermal radiation in a narrowed range of energies, useful for efficient conversion to electricity. Structures fabricated herein demonstrate the necessary combination of thermal stability and selective thermal emission for TPV applications. It is hoped that this work will enable the fruition of high efficiency TPV systems incorporating a 3D photonic crystal thermal emitter. Three-dimensional aluminum architectures were fabricated using electrodeposition inside self-assembled templates for energy storage applications. Finally, complex 3D gold architectures were fabricated using a more advanced template fabrication technique, direct laser writing, in combination with electrodeposition for chiral metamaterial applications.
thermophotovoltaics, photonic crystals, self-assembly, energy storage, Metamaterials
University of Illinois - Urbana-Champaign
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University of Illinois at Urbana-Champaign