Tuning the optical properties of GaAs solar cell through triple-layer antireflection coatings

Abstract

Solar cells must be efficient in order to reduce optical losses. A variety of light-trapping techniques are employed to reduce optical losses, especially those due to reflections. Solar cells are coated with antireflective coatings (ARCs) to reduce reflected light. The optimum triple-layer antireflective coatings (TLARC) on a high index subsrate has been investigated in this paper. An evaluation of the reflectivity of TLARC materials over visible and near-IR wavelength ranges is performed with the suitable substrate material. Moreover, reflectance can be affected by the important parameter of thickness of the antireflection coatings. The reflectance, transmittance, short circuit current density, external quantum efficiency, and charge carrier generation rate are calculated with wavelength for various thickness of ARC. The optimized thickness of d1 = 120 nm, d2 = 167 nm, and d3 = 175 nm produces zero reflectance at wavelengths of 400 nm and 700 nm, respectively. Following our investigations, we conclude that TLARCs MgF2/SiO/ZnSe are the best ARC candidates in a broad wavelength range of 400–1400 nm for GaAs solar cell.