Bandgap-engineered MXene-g-C3N4 interfacial layer for enhanced charge carrier dynamics in perovskite solar cells
This research illustrates the crucial significance of bandgap engineering in enhancing the performance of perovskite solar cells (PSCs). By strategically including a graphitic carbon nitride (g-C3N4) and Ti3C2 MXene (MXGCN) heterostructure as an nterfacial layer between the SnO2 electron transport layer and the CH3NH3PbI3 perovskite absorber, we achieved considerable enhancements in device efficiency and stability. The π-conjugated structure of MXGCN promotes effective charge carrier separation and transport, whereas the diminished work function of g-C3N4 improves carrier mobility. The MXGCN heterostructure efficiently passivates defects in the perovskite layer, mitigating non-radiative recombination losses. The synergistic effects led to a significant enhancement in power conversion efficiency (PCE) from 21.20 % to 23.80 %. Furthermore, the devices demonstrated remarkable long-term stability, maintaining over 91 % of their initial efficiency after 700 h of storage. These findings highlight the potential of MXGCN-based interfacial engineering to transform the domain of perovskite solar cells.