Highly efficient selective metamaterial absorber for high-temperature solar thermal energy harvesting

Hao Wang, Vijay Prasad Sivan, Arnan Mitchell, Gary Rosengarten, Patrick Phelan, Liping Wang

Research output: Contribution to journalArticle

98 Scopus citations

Abstract

In this work, a selective solar absorber made of nanostructured titanium gratings deposited on an ultrathin MgF2 spacer and a tungsten ground film is proposed and experimentally demonstrated. Normal absorptance of the fabricated solar absorber is characterized to be higher than 0.9 in the UV, visible and, near infrared (IR) regime, while the mid-IR emittance is around 0.2. The high broadband absorption in the solar spectrum is realized by the excitation of surface plasmon and magnetic polariton resonances, while the low mid-IR emittance is due to the highly reflective nature of the metallic components. Further directional and polarized reflectance measurements show wide-angle and polarization-insensitive high absorption within solar spectrum. Temperature-dependent spectroscopic characterization indicates that the optical properties barely change at elevated temperatures up to 350 C. The solar-to-heat conversion efficiency with the fabricated metamaterial solar absorber is predicted to be 78% at 100 C without optical concentration or 80% at 400 C with 25 suns. The performance could be further improved with better fabrication processes and geometric optimization during metamaterial design. The strong spectral selectivity, favorable diffuse-like behavior, and good thermal stability make the metamaterial selective absorber promising for significantly enhancing solar thermal energy harvesting in various systems at mid to high temperatures.

Original languageEnglish (US)
Article number7621
Pages (from-to)235-242
Number of pages8
JournalSolar Energy Materials and Solar Cells
Volume137
DOIs
StatePublished - Jun 2015

Keywords

  • High temperatures
  • Metamaterials
  • Optical properties
  • Solar absorbers

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Renewable Energy, Sustainability and the Environment
  • Surfaces, Coatings and Films

Fingerprint Dive into the research topics of 'Highly efficient selective metamaterial absorber for high-temperature solar thermal energy harvesting'. Together they form a unique fingerprint.

  • Cite this