Tailorable bandgap-dependent selective emitters for thermophotovoltaic systems

Selective emitters are crucial in thermophotovoltaic (TPV) systems as they can selectively tailor the incident light to match with the bandgap of photovoltaic (PV) cell, thus greatly increasing the system efficiency. However, further progress has been hampered by the limitation in designing high performance selective emitters with spectrally emissive selectivity and compatible ability to different PV cells. In this study, we propose a design strategy to realize tailorable bandgap-dependent selective emitters based on metasurfaces by combing the two-resonance response of surface plasmon polaritons (SPPs) and magnetic polaritons (MPs). The emission spectrum can be manipulated and matched to various PV cells with different bandgap by simply changing the size and period of the meta-atoms in metasurface. We design and experimentally demonstrate a selective emitter appealing to GaSb PV cells, which presents near-perfect emissivity (above 0.96) above the bandgap wavelength (from 0.9 mu m to 1.54 mu m ) with polarizationinsensitive and angle-insensitive features. Moreover, the emitter shows a high figure of merit (FOM, of 0.85), and the efficiency of TPV system can be expected to be 27% at 1473K. The proposed strategy and designed emitter may pave a reliable route for improving the performance of TPV systems. (c) 2022 Elsevier Ltd. All rights reserved.

Automated summary

Selective emitters are crucial for thermophotovoltaic (TPV) systems as they enhance system efficiency by tailoring incident light to match with the bandgap of photovoltaic (PV) cells. This study proposes a design strategy based on metasurfaces to achieve tailorable bandgap-dependent selective emitters, improving the performance of TPV systems.