Spectral and Spatial Coherent Emission of Thermal Radiation from Metal-Semiconductor Nanostructures

Publication Year:
2012
Usage 6
Abstract Views 4
Downloads 2
Repository URL:
https://scholar.afit.edu/etd/1184
Author(s):
McConnell, Shane N.
Tags:
Nanostructures; Infrared; Plasmonics; Radiative transfer; Plasma and Beam Physics
thesis / dissertation description
The spectral and spatial radiative properties of coherent thermal emission in the mid- and far-IR through the use of micro and nano-structured metal-semiconductor materials were designed and demonstrated experimentally. Using an implementation of the Rigorous Coupled Wave Analysis and Computer Simulation Technology (CST), two structures were designed to selectively emit at mid- and far-IR wavelengths, a 1-D truncated multilayer resonator and a 3-D hybrid photonic crystal (PC)-multilayer. A High Impulse Power Magnetron Sputtering (HIPIMS) deposition technique was used to fabricate two silver-germanium-silver (Ag-Ge-Ag) resonating structures with layer thicknesses of 6-240-160 nm for one sample and 6-700-200 nm for the other. Ellipsometric measurements showed significant disagreement between HIPIMS-deposited material properties and bulk values found in literature. From radiance measurements, spectral emittance was directly derived and compared to the emittance inferred from reflectance measurements. It was established that inferring emittance can help to approximate the expected emission from a structure, but it is not an exact method of determining the actual emittance. Using CST, the PC-multilayer was modeled to examine its spatial coherence. Initial fabrication results of the PC-multilayer involving both HIPIMS deposition of a Ge-Ag-Ge-Ag (4-12-270-200 nm) multilayer, and focused ion beam milling of a square hole array are also presented.