Interface Engineering With Annealed MXene and SAM Molecules for High‐Performance Inverted Perovskite Solar Cells

ABSTRACT The strong interaction between indium tin oxide (ITO) substrate and uniformly distributed self‐assembled molecules (SAMs) are critical for the excellent performance of inverted perovskite solar cells (IPSCs). Nevertheless, achieving uniform SAM distribution and robust stability on ITO substrate remains a significant challenge. Herein, the heat‐treated 2D Ti 3 C 2 T x (A‐Ti 3 C 2 T x ) layer is introduced into between 4‐(11H‐benzo[a]carbazol‐11‐yl)butyl (4‐PhCz) SAM layer and the ITO substrate, constructing the stable ITO/A‐Ti 3 C 2 T x /SAM anode interface. The results reveal that A‐Ti 3 C 2 T x not only can form a strong bond with the ITO substrate, but also establish robust tridentate interaction with SAM molecule through Ti─O─P and Ti─O─P bonds, enhancing stability of anode interface. This type of anode interface can enhance interfacial charge transport and optimize energy level alignment in IPSC, also plays a positive role in promoting perovskite grain growth and regulates residual stress. Encouragingly, the A‐Ti 3 C 2 T x ‐based IPSC demonstrates an outstanding efficiency of up to 26.78% (certified 26.44%) for 0.08 cm 2 with excellent stability, which is the highest PCE reported so far in PSCs utilizing MXene materials. And flexible A‐Ti 3 C 2 T x ‐based IPSC exhibits superior flexibility. This work provides an effective strategy for enhancing the mechanical and thermal stability of anode interface, as well as gives an in‐depth mechanism analysis.