Enhancement the optical properties of thin film solar cells using new materials and designs of anti-reflection coating

In this research, a front layer of indium tin oxide (ITO) is added on the top surface of copper zinc tin sulfide (CZTS)/zinc oxide (ZnO) thin film solar cell. The goal of this paper is to improve the absorption values against the angle of incidence through visible wavelengths. The transfer matrix approach and the finite element method were extensively used in the design and simulation process. The numerical findings are investigated with the help of COMSOL multiphysics software as well. Recently, it has been found that the angle of incidence significantly reduces the solar cell absorption. To prevent such increment of absorption losses as the angle of incidence rises, the numerical findings have deduced that it may therefore be of interest to include an anti-reflecting coating of ternary one-dimensional photonic crystals on a single unit cell. Meanwhile, the anti-reflective coating is designed with three different geometries: planar, convex, and concave. The investigated results demonstrated that the concave geometry is efficient in controlling the absorption losses of the designed CZTS/ZnO thin film solar cell against the increase in the angle of incidence. In this regard, for an angle of incidence less than 50°, the solar cell absorption values remain greater than 0.9055 all over the visible spectrum. Therefore, a relatively high performance of this cell is strongly expected.