title: Tailoring photonic metamaterial resonances for thermal radiation.
abstract: Selective solar absorbers generally have limited effectiveness in unconcentrated sunlight, because of reradiation losses over a broad range of wavelengths and angles. However, metamaterials offer the potential to limit radiation exchange to a proscribed range of angles and wavelengths, which has the potential to dramatically boost performance. After globally optimizing one particular class of such designs, we find thermal transfer efficiencies of 78% at temperatures over 1,000°C, with overall system energy conversion efficiencies of 37%, exceeding the Shockley-Quiesser efficiency limit of 31% for photovoltaic conversion under unconcentrated sunlight. This represents a 250% increase in efficiency and 94% decrease in selective emitter area compared to a standard, angular-insensitive selective absorber.PACS: 42.70.Qs; 81.05.Xj; 78.67.Pt; 42.79.Ek.
authors: Institute for Soldier Nanotechnologies, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139, USA. bermel@mit.edu.
authors: Peter
authors: P
authors: Bermel
authors: Michael
authors: M
authors: Ghebrebrhan
authors: Michael
authors: M
authors: Harradon
authors: Yi Xiang
authors: YX
authors: Yeng
authors: Ivan
authors: I
authors: Celanovic
authors: John D
authors: JD
authors: Joannopoulos
authors: Marin
authors: M
authors: Soljacic