Strongly Anchored Dion-Jacobson Perovskite for Efficient Blue Light-Emitting Diodes

Area of Science:

• Materials Science
• Solid-State Chemistry
• Optoelectronics

Background:

• Dion-Jacobson (DJ) perovskites offer advantages over Ruddlesden-Popper (RP) perovskites for blue perovskite light-emitting diodes (PeLEDs).
• Weak hydrogen bonding in DJ perovskites hinders crystallization control and increases defect density, impacting film quality and device performance.
• Developing stable and efficient blue PeLEDs remains a significant challenge in optoelectronic research.

Purpose of the Study:

• To optimize Dion-Jacobson (DJ) perovskite films for enhanced blue light-emitting diode (PeLED) performance.
• To address challenges in crystallization and defect density associated with DJ perovskites.
• To introduce a novel precursor for stabilizing DJ perovskite structures and improving emission efficiency.

Main Methods:

• Introduction of a novel cesium octafluoroadipate (CsOFAA) precursor into DJ perovskite formulations.
• Utilizing coordination and halogen-halogen bonds for strong anchoring of the CsOFAA precursor to the perovskite structure.
• Characterization of film quality, crystallization, defect density, and optoelectronic properties of the modified DJ perovskites.

Main Results:

• The CsOFAA precursor effectively anchored the DJ perovskite structure through strong interactions.
• Stabilization of the DJ perovskite structure and significant suppression of nonradiative recombination were achieved.
• High external quantum efficiencies (EQEs) of 15.2% (490 nm), 10.0% (485 nm), and 8.3% (479 nm) were demonstrated for blue PeLEDs.
• The optimized DJ perovskite films exhibited efficient and stable blue emission.

Conclusions:

• The novel CsOFAA precursor successfully optimized DJ perovskite films for high-performance blue PeLEDs.
• Strong interactions provided by CsOFAA enhance structural stability and reduce defects, leading to improved device efficiency.
• This work presents the most efficient blue DJ PeLEDs reported to date, paving the way for advanced optoelectronic applications.