Hexagonal array micro-convex patterned substrate for improving diffused transmittance in perovskite solar cells

In the past decade, the fastest development in solar cell research has occurred for perovskite solar cells. Owing to the favorable properties of perovskite materials, perovskite solar cells exhibit excellent power conversion efficiencies and there appears great potential for future development. In this paper, we report the fabrication of a substrate with excellent optical properties by incorporating hexagonal array micro-convex (HAMC) nanostructures in it before integration with the electrode (indium tin oxide and zinc oxide) and the halide for use in organic-inorganic perovskite solar cells. This was fabricated using nanoimprint lithography which showed excellent throughput and involved simple processing methods. The HAMC nanostructured substrate showed strong light scattering as compared to that of the conventional substrate. This resulted in the increase of current density of the fabricated solar cell from 19.45 mA/cm² (un-patterned substrate) to 20.92 mA/cm² (nanostructured substrate) with accompanying increase in the external quantum efficiency and a satisfactory performance by the perovskite solar cell.