High temperature selective emitters via critical coupling of weak absorbers

Patent metadata

Field	Value
Publication number	US-10819270-B2
Application number	US-201815923909-A
Country	US
Kind code	B2
Filing date	Mar 16, 2018
Priority date	Mar 16, 2018
Publication date	Oct 27, 2020
Grant date	Oct 27, 2020

Abstract

Tailoring the emission spectra of a solar thermophotovoltaic emitter away from that of a blackbody, thereby minimizing transmission and thermalization loss in the energy receiver, is a viable approach to circumventing the Shockley-Queisser limit to single junction solar energy conversion. Embodiments allow for radically tuned selective thermal emission that leverages the interplay between two resonant phenomena in a simple planar structure—absorption in weakly-absorbing thin films and reflection in multi-layer dielectric stacks. A virtual screening approach is employed based on Pareto optimality to identify a small number of promising structures for a selective thermal emitter from a search space of millions, several of which approach the ideal values of a step-function selective thermal emitter.

First claim

What is claimed is:

1. A computer implemented system for identifying photonic crystals comprising:
a processor; and
a tangible computer-readable medium operatively connected to the processor and including computer code configured to:
determine emissivity for candidate emitter structures;
select an absorber to pair with the candidate emitter structures;
determine spectral conversion efficiency (η s ) and useful power (P) as figures of merit;
perform a Pareto optimization using the figures of merit; and
determine a degree of critical coupling of at least a portion of the candidate emitter structures and the selected absorber.

2. The computer implemented system of claim 1 , further comprising computer code configured to:
select an operating temperature for a photovoltaic.

3. The computer implemented system of claim 1 , wherein the figures of merit are spectral conversion efficiency (η s ) and useful power (P).

4. The computer implemented system of claim 1 , further comprising computer code configured to, prior to identifying if a parameter is Pareto optimal, determine absorption spectrum for an alloy layer of the candidate emitter structure.

5. The computer implemented system of claim 4 , further comprising computer code configured to, prior to identifying if a parameter is Pareto optimal, determine stored energy spectrum of a Bragg reflector of the candidate emitter structure.

6. The computer implemented system of claim 5 , wherein the parameters are selected from the group consisting of Bragg reflector dielectric layer thicknesses, Bragg reflector refractive indices, Bragg reflector number of such pair layers, Λ BR and the alloy layer composition, operating temperature, bandgap of an associated photovoltaic.

7. The computer implemented system of claim 5 , wherein the candidate emitter comprises a refractory metal, the Bragg reflector and the alloy layer.

8. The computer implemented system of claim 7 , wherein the refractory metal is tungsten and the alloy layer is W—Al 2 O 3 alloy.

Assignees

• Uchicago Argonne Llc
• William Paterson Univ Of New Jersey

Inventors

• Martinson Alex B
• Jeon Nari
• Gray Stephen K
• Foley Iv Jonathan J

Classifications

• H10K59/876

  comprising a resonant cavity structure, e.g. Bragg reflector pair · CPC title

• H10D89/10

  Integrated device layouts · CPC title

• H10H20/841

  Reflective coatings, e.g. dielectric Bragg reflectors · CPC title

• H10H20/814

  having reflecting means, e.g. semiconductor Bragg reflectors · CPC title

• H10F77/488

  Reflecting light-concentrating means, e.g. parabolic mirrors or concentrators using total internal reflection · CPC title