Passive cooling of solar cells with a comprehensive photonic approach

We present a comprehensive photonic approach for passive cooling of solar cells by simultaneously performing radiative cooling while also selectively utilizing the sunlight. We design a photonic cooler made of multilayer dielectric stack that can strongly radiate heat through its thermal radiation while also significantly reflecting the solar spectrum in sub-band gap and ultraviolet regime. We show that applying this photonic cooler on solar panel can cool the solar cell by over 5.6K in a typical terrestrial operating condition. Our technique points to an optimal photonic approach for passive cooling of solar cells and can be readily implemented as a retrofit for current photovoltaic modules to improve both efficiency and reliability.