Multidentate Molecular Suturing at Dual Interfaces Enables Highly Efficient Perovskite Light-Emitting Diodes

Perovskite light-emitting diodes (PeLEDs) have emerged as a promising technology for future displays owing to their prominent optoelectronic properties. However, inefficient charge injection and nonradiative recombination at the interfaces, alongside defective crystal growth, remain the primary bottlenecks for efficient LED devices. Herein, we propose a "molecular suturing" strategy that synchronously stabilizes the interface and directs crystal growth using a multifunctional ligand. We employ methyl bis(2,2,2-trifluoroethyl) phosphonoacetate (MBTPA), which features cooperative carbonyl (C = O), phosphoryl (P = O), and trifluoromethyl (─CF₃) groups. The C = O and P = O groups chemically bind to defect sites, forming coordination interactions with undercoordinated Pb²⁺ and halide vacancies. Concurrently, the ─CF₃ moieties establish robust hydrogen-bond interactions with hole injection layer. By providing these two complementary interactions on opposite sides, MBTPA effectively "sutures" the buried interface between the perovskite and the hole-transport layer, strengthening interfacial adhesion and promoting more efficient hole injection. Consequently, MBTPA-modified PeLEDs achieve bright blue emission at 485 nm with a peak external quantum efficiency (EQE) of 23.14%, and green emission at 513 nm with a peak EQE of 27.05%. This molecular suturing strategy provides an effective route for simultaneous control of interfacial chemistry and crystallization, offering a generalizable approach for performance enhancement in perovskite optoelectronic devices.