In Situ Interface Reaction Enables Efficient Deep-Blue Perovskite Light-Emitting Diodes

Area of Science:

• Materials Science
• Optoelectronics
• Solid-State Chemistry

Background:

• Blue perovskite light-emitting diodes (PeLEDs) are crucial for next-generation displays.
• Fabricating high-quality blue perovskites is challenging due to defects, ion migration, and poor charge transport.

Purpose of the Study:

• To develop a novel method for preparing high-quality, spectrally stable deep-blue perovskite films.
• To address the challenges in blue PeLED fabrication using an in situ interface reaction.

Main Methods:

• Engineered a rapid in situ interface reaction at the perovskite/PEDOT:PSS buried interface.
• Incorporated lithium salicylate (SAL) into the perovskite precursor to initiate proton exchange.
• Formed a multifunctional PSS-Li interfacial layer to modulate perovskite nucleation and growth.

Main Results:

• Achieved compact, uniform, small-grained deep-blue CsPb(Br/Cl)3 films with reduced trap densities.
• Demonstrated enhanced quantum confinement and optimized charge dynamics.
• Attained a record external quantum efficiency of 16.3% at 468 nm for spectrally stable deep-blue PeLEDs.

Conclusions:

• The engineered interface reaction is a novel and effective method for high-quality blue perovskite film preparation.
• The PSS-Li interfacial layer significantly improves perovskite film quality and device performance.
• This approach enables the integration of high-performance PeLEDs for active-matrix display applications.