Controlling Interfacial Amidation Reaction Rate to Regulate Crystal Growth toward High-Performance FAPbBr₃-Based...

Area of Science:

• Materials Science
• Optoelectronics
• Chemistry

Background:

• Controlling interfacial reactions is crucial for high-performance zinc oxide (ZnO)-based inverted perovskite light-emitting diodes (PeLEDs).
• Existing near-infrared PeLEDs achieve high external quantum efficiency (EQE), but green PeLEDs suffer from performance limitations due to interfacial reactions between perovskites and ZnO films.
• Violent interfacial reactions between bromine-based perovskites and ZnO films hinder the efficiency and stability of inverted green PeLEDs.

Purpose of the Study:

• To develop a controllable interfacial amidation strategy for bromine-based perovskites and magnesium-doped ZnO (ZnMgO) films.
• To regulate the crystallization of FAPbBr3 and improve the performance of inverted green PeLEDs.
• To overcome the limitations of current green PeLED technology and achieve state-of-the-art electroluminescence.

Main Methods:

• Utilized caprylyl sulfobetaine (SFB) to mediate interfacial amidation between bromine-based perovskites and ZnMgO films.
• SFB molecules were employed to interact with formamidinium bromide, slowing the amidation reaction between formamidinium and carboxylate groups.
• Incorporated benzylamine for passivation, enabling direct deposition of FAPbBr3 bulk film with single-crystal characteristics on a ZnMgO substrate.

Main Results:

• Achieved controllable interfacial amidation, regulating FAPbBr3 crystallization and forming single-crystal characteristics.
• Obtained a high photoluminescence quantum yield of over 80% for the FAPbBr3 film.
• Demonstrated inverted green PeLEDs with a peak EQE exceeding 20% at high luminance (120,000 cd m⁻²) and a half-lifetime of 26 minutes at 11,000 cd m⁻².
• Reported state-of-the-art inverted green electroluminescence performance.

Conclusions:

• The developed interfacial amidation strategy effectively resolves issues of violent interfacial reactions in green PeLEDs.
• This approach provides a viable pathway toward achieving high-performance inverted green PeLEDs with enhanced efficiency and stability.
• The findings represent a significant advancement in the field of perovskite optoelectronics, particularly for green light emission.