Determining the Effectiveness of Radiative Cooler-Integrated Solar Cells

Abstract

The power-conversion efficiency of solar cells (SCs) is reduced at high temperatures. A radiative cooling process can be implemented to overcome this issue. The radiative cooler (RC) presents considerable potential in the design of an ideal broadband emitter, which emits heat through the entire atmospheric transmittance window for devices with operating temperatures that significantly exceed the ambient temperature. However, the performance of these devices varies based on the type of SCs. This study aims to determine the dependency of the radiative cooling power for various types of SCs and proposes the multi-junction SC (MJSC), which is the SC that benefits the most from RCs. The integrated cooler is designed with a micro-grating which can enhance the emissivity within entire atmospheric transmittance window and can also lead to the light-trapping aspect in the solar spectrum. Outdoor field tests demonstrate both the enhanced cooling performance and the power conversion efficiency of the proposed MJSC when compared to a conventional glass-mounted MJSC under direct sunlight of approximate to 900 Wm(-2) including a temperature drop of approximate to 6 degrees C and minimization of the variation of the open-circuit voltage to approximate to 6%. Future research is expected to develop a theoretical bridge between the field of SCs and radiative cooling.