Virtual Design and Analysis of Pareto Optimal Emitter Structures for Thermophotovoltaic Applications

In this work, we focus on composite planar nanostructures that leverage the interaplay between two resonant phenomena that can be realized in simple planar nanoelements: resonant absorption in weakly-absorbing nanoscale films and reflection resonances in multi-layer dielectric stacks (Bragg Reflectors). The interplay between these resonances enables spectral tunability of the composite nanostructures, and yields structures whose thermal emission properties approach the ideal limit of a step-function emitter.
We combined rigourous electrodynamics calculations with a virtual screening technique based on Pareto optimality to identify a small number of promising structures from a search space of more than 5 million structures, and we have begun experimentally realizing and characterizing structures from this small subset. The results we will report on are an important step towards realizing efficient and robust structures for solar and thermal energy conversion.