Simulation and investigation of perovskite/nano-pyramidal GeSe solar cell: Realizing high efficiency by controllable light trapping

Perovskite Solar Cells (PSC) have been elicited much interest within the photovoltaic industry due to their many performance advantages. One of the effective ways to enhance the Power Conversion Efficiency (PCE) of PSCs is to minimize light and electrical losses. To this end, we have focused on the use of nanostructured light absorbers in PSCs and have simulated these structures to understand their effects on the light absorption and electrical output of the cells. Given that perovskites do not absorb light of wavelengths higher than 800 nm, we used an extra absorption material - GeSe - which has a narrower bandgap and a wider absorption spectrum in order to increase the amount of light absorbed. GeSe Nano-pyramids (GSNPs) were also used in the active layer (perovskite) to manage input light. The use of such structures improved the short-current density (J(sc)) of the cell. The effects of changing the height of GeSe NPs were also investigated to determine the best height of NPs that produced the highest PCE. The optimal structure had NP height of 100 nm and resulted in J(sc) and PCE values of 24.83 mA/cm(2) and 18.49%, respectively, which were 25.65% and 21.80%, improvements over the planar design, respectively.