Reassessment of different antireflection coatings for crystalline silicon solar cell in view of their passive radiative cooling properties.

• Passive radiative cooling of c-Si solar cell via transparent thin film. • Cooling through atmospheric window (8–13 µm wavelength). • The hemispherical and angular emissivity of thin film. • SiO 2 , TiO 2 , Si 3 N 4 , Al 2 O 3 and HfO 2 compared for 3-D emissive properties. In outdoor condition, the performance of the commercial solar photovoltaic (PV) modules depends on various parameters like (1) amount of direct solar radiation, (2) ambient temperature, (3) the location of installation, (4) wind speed, (6) aerosol, and most of these parameters are uncontrollable. The first two of these parameters increase the solar cell operating temperature which in turn decreases the performance of the solar cell. This simulation-based study presents the development of a passive radiative cooling system for a simple flat crystalline silicon (c-Si) solar cell using a thin film of SiO 2 , Al 2 O 3 , Si 3 N 4 , HfO 2 or TiO 2. Some of these materials are being used as an antireflection coating (ARC) in the commercial solar panel for having a suitable refractive index (n) and very low extinction coefficient (k) values in 300–1200 nm wavelength range. In the 8–13 µm wavelength range, the variation of emissivity of the materials w.r.t. thickness and angle have been calculated. The thickness of ARC, the absorptivity of Silicon, the emissivity of ARC in the atmospheric window was also estimated. Suitable ARC cum emissive layer helps the solar cell in absorptivity improvement as well as keeping its temperature near the ambient temperature. The present study finds that Si 3 N 4 is having a higher emissive power than the other materials and increases (10–161.63 W m−2) with the increase in thickness from 20 to 1000 nm in 8–13 µm wavelength range. Material like SiO 2 and Al 2 O 3 have emissivity lower than Si 3 N 4 of comparable thickness. [ABSTRACT FROM AUTHOR]