V-Gap Engineered Graphitic Carbon Nitride as an Electron Transport Layer for Methylammonium Lead Iodide Perovskite Solar Cells: Experimental and Simulation Studies

In pursuit of improving the efficiency of perovskite solar cells, investigation of various types of electron transport materials has gained significant attention. Among them, two-dimensional material graphitic carbon nitride (g-C₃N₄) is one. In this study, g-C₃N₄ was investigated as an electron transport layer for hybrid perovskite solar cells. To study the effect of solar cell efficiency, devices with and without g-C₃N₄ were fabricated. The g-C₃N₄-incorporated device (ITO/PEDOT:PSS/MAPbI₃/Nafion:g-C₃N₄/Al) exhibited an improved power conversion efficiency of ∼13% compared to the reference device ITO/PEDOT:PSS/MAPbI₃/Nafion/Al, i.e., ∼9%. Further, the device level mechanism and solar cell properties were analyzed by device simulations. The experimental and simulations studies suggested that the significant change in efficiency could be due to efficient charge transfer across the interface and reduced recombination. This finding paves the way for further exploration of graphitic carbon nitride as a transport layer in perovskite solar cells. The successful optimization of the g-C₃N₄ transport layer may offer a stable and cost-effective transport layer for perovskite solar cells.