Optimization of Thermophotovoltaic Systems Using One Dimensional Photonic Crystal Optical Filters with a Graded Index of Refraction Profile

This thesis investigates the enhancement of thermophotovoltaic (TPV) systems using one-dimensional photonic crystals (1DPC) with a graded index of refraction as optical filters. It compares three 1DPC configurations: graded index, traditional quarter-wave, and modified quarter-wave stacks, to improve TPV performance. Designed for TPV applications, these filters aim to increase in-band transparency and minimize absorption while ensuring high out-of-band reflection. Graded index 1DPCs, made of porous silicon dioxide and solid zirconium dioxide, exhibit low absorbance across a broad spectrum, offering a novel approach in TPV applications. Significantly, a double-stack graded filter at an emitter temperature of 2000 K achieved 74% in-band transmittance and 55% out-of-band reflectance. Highlighting a design trade-off, the study presents an optimal filter configuration that yields a 24% system efficiency and a power density of 6.9 W/cm^2. The analysis focuses on system efficiency and power output, emphasizing the advancement in TPV efficiency through the application of graded index 1DPC filters.