Power Density and Efficiency of Thermophotovoltaic Energy Conversion Using a Photonic-Crystal Emitter and a $\hbox {2}$ -D Metal-Grid Filter

Three-dimensional metallic photonic crystals have been suggested to be ideal candidates for thermal emitters in thermophotovoltaic energy conversion systems due to their high emission power in the allowed passband and also their emission suppression in the long-wavelength tail. In this paper, calculations were performed to compare a photonic-crystal emitter and a blackbody emitter in the thermodynamic limit of the maximum power density and efficiency that are achievable with an ideal photovoltaic cell. Additionally, realistic-source and GaSb photovoltaic-cell optical characteristics and a novel metal-grid filter are incorporated into the calculations. With an ideal antireflection coating, the measured photonic-crystal radiation was found to give a source electrical power density of 7.77 W/cm² and a system efficiency of 47.58% with an effective source temperature of 1535 K.