Nanoscale grating-based perovskite solar cell with improved efficiency

Abstract MAPbI 3 perovskite-based solar cell (PSC) has attracted much attention due to its high absorption rate. The top flat electrode degrades the behavior of PSC due to limiting the light reached to the absorber layer, which reduces the efficiency. In this study, the influence of texturing the top FTO electrode surface with a triangular saw-tooth grating on both the optical and electrical performance is reported. The interference effects are also considered in this work by modeling the PSC structure as a Fabry–Perot resonator. In this regard, the finite difference time domain method is utilized to precisely simulate the optical characteristics of the nano-structural design. Also, the optical behavior of PSC is studied at different triangular grating (TG) structures and dimensions at which the light absorption is maximized. Furthermore, the effect of absorber thickness and defect density on the optoelectronic performance is investigated. We configured the conversion efficiency ( η ) of the proposed PSC structure by using the bulk and Langevin recombination mechanisms. The proposed grating structure enhances the light coupling, and hence the light absorption and the generated current density are increased. For absorber thickness of 350 nm, we reported a maximum conversion efficiency ( η ) of 19.5% for the proposed triangular grating (TG) structure with an enhancement of 19.6% compared to the structure with a flat FTO layer. As the defect density is increased from 10 12 cm −3 to 10 18 cm −3 , the efficiency of the optimum TG PSC is reduced from 19.5% to 10.1%, respectively. The simulation results, therefore, contribute to the understanding of the PSC-based MAPbI 3 design and can be used to improve its physical behavior.