High-efficiency solar-thermophotovoltaic system equipped with a monolithic planar selective absorber/emitter

Makoto Shimizu, Asaka Kohiyama, Hiroo Yugami

Research output: Contribution to journalArticlepeer-review

61 Citations (Scopus)


We demonstrate a high-efficiency solar-thermophotovoltaic system (STPV) using a monolithic, planar, and spectrally selective absorber/emitter. A complete STPV system using gallium antimonide (GaSb) cells was designed and fabricated to conduct power generation tests. To produce a high-efficiency STPV, it is important to match the thermal radiation spectrum with the sensitive region of the GaSb cells. Therefore, to reach high temperatures with low incident power, a planar absorber/emitter is incorporated for controlling the thermal radiation spectrum. This multilayer coating consists of thin-film tungsten sandwiched by yttria-stabilized zirconia. The system efficiency is estimated to be 16% when accounting for the optical properties of the fabricated absorber/emitter. Power generation tests using a high-concentration solar simulator show that the absorber/emitter temperature peaks at 1640 K with an incident power density of 45 W/cm2, which can be easily obtained by low-cost optics such as Fresnel lenses. The conversion efficiency became 23%, exceeding the Shockley-Queisser limit for GaSb, with a bandgap of 0.67 eV. Furthermore, a total system efficiency of 8% was obtained with the view factor between the emitter and the cell assumed to be 1.

Original languageEnglish
Article number053099
JournalJournal of Photonics for Energy
Issue number1
Publication statusPublished - 2015 Jan 1


  • gallium antimonide
  • solar energy
  • spectral control of thermal radiation
  • thermophotovoltaic

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Renewable Energy, Sustainability and the Environment


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