A Comprehensive Photonic Approach for Solar Cell Cooling

The heating of a solar cell has significant adverse consequences on both its efficiency and its reliability. Here to fully exploit the cooling potential of solar cells, we experimentally characterized the thermal radiation and solar absorption properties of current silicon solar cells and, on the basis of such experimental characterization, propose a comprehensive photonic approach by simultaneously performing radiative cooling while also selectively utilizing sunlight. In particular, we design a photonic cooler made of one dimensional photonic films that can strongly radiate heat through its thermal emission while also significantly reflecting the solar spectrum in the sub-band-gap and ultraviolet regimes. We show that applying this photonic cooler to a solar panel can lower the cell temperature by over 5.7 degrees C. We also show that this photonic cooler can be used in a concentrated photovoltaic system to significantly reduce the solar cell temperature or required cooling power. This photonic cooler can be readily implemented in current photovoltaic modules as a retrofit to improve both efficiency and lifetime. Our approach points to an optimal photonic approach for thermal management of solar cells.