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

Area of Science:

• Materials Science
• Optoelectronics
• Nanotechnology

Background:

• Perovskite light-emitting diodes (PeLEDs) show promise for displays due to excellent optoelectronic properties.
• Key challenges include inefficient charge injection, nonradiative recombination at interfaces, and crystal defects.
• These limitations hinder the development of high-performance PeLED devices.

Purpose of the Study:

• To introduce a "molecular suturing" strategy for simultaneous interface stabilization and crystal growth control in PeLEDs.
• To enhance charge injection and reduce defects in perovskite layers.
• To improve the overall efficiency and performance of PeLED devices.

Main Methods:

• Employed a multifunctional ligand, methyl bis(2,2,2-trifluoroethyl) phosphonoacetate (MBTPA), featuring carbonyl, phosphoryl, and trifluoromethyl groups.
• MBTPA forms coordination interactions with perovskite defect sites (Pb2+ and halide vacancies) and hydrogen bonds with the hole injection layer.
• This "suturing" strengthens the perovskite/hole-transport layer interface and promotes efficient hole injection.

Main Results:

• MBPTA modification successfully stabilized the perovskite interface and directed crystal growth.
• Achieved bright blue emission at 485 nm with a peak external quantum efficiency (EQE) of 23.14%.
• Demonstrated green emission at 513 nm with a peak EQE of 27.05%.

Conclusions:

• The molecular suturing strategy effectively addresses interfacial and crystallization bottlenecks in PeLEDs.
• This approach offers a generalizable method for enhancing the performance of perovskite optoelectronic devices.
• MBPTA-modified PeLEDs exhibit significantly improved efficiency and emission characteristics.