Charge Environment and Perovskite Crystallization Regulation Interface Engineering with Molecular Bridge for...

Area of Science:

• Materials Science
• Optoelectronics
• Chemistry

Background:

• Deep-blue perovskite light-emitting diodes (PeLEDs) face challenges with charge injection and crystallization.
• Reduced-dimensional perovskites (RDPs) are promising but require interface optimization for high performance.

Purpose of the Study:

• To engineer the interface between RDPs and hole transporting layers using a molecular bridge.
• To improve charge injection, energy level alignment, and crystallization kinetics in RDP films.
• To enhance the performance and stability of deep-blue PeLEDs.

Main Methods:

• Implementation of an interfacial chemical molecular bridge between RDP and poly(9-vinylcarbazole) (PVK).
• Analysis of the molecular bridge's interface reaction with PVK.
• Investigation of the bridge's effect on RDP crystallization dynamics and defect renovation.

Main Results:

• The molecular bridge facilitated hole injection and improved energy level alignment.
• RDP crystallization dynamics were regulated, inhibiting halide clusters and small-n phases.
• Optimized RDP films showed a photoluminescence quantum yield (PLQY) of 71.69% at 447 nm.
• Modified PeLEDs achieved an external quantum efficiency (EQE) of 4.48% with stable deep-blue electroluminescence.

Conclusions:

• The molecular bridge effectively engineers the RDP/PVK interface, enhancing charge transport and film quality.
• This strategy leads to high-performance, spectrally stable deep-blue PeLEDs.
• Interface engineering is crucial for advancing RDP-based optoelectronic devices.