Exploiting a Multiphase Pure Formamidinium Lead Perovskite for Efficient Green-Light-Emitting Diodes

Area of Science:

• Materials Science
• Optoelectronics
• Solid-State Chemistry

Background:

• Formamidinium (FA)-based perovskites show promise in optoelectronics.
• Optimal composition for perovskite compounds remains a challenge.
• Perovskite light-emitting diodes (PeLEDs) require efficiency and stability improvements.

Purpose of the Study:

• To enhance the performance of PeLEDs through composition and phase engineering.
• To investigate the effect of phase composition on FA-based perovskites.
• To achieve higher efficiency and improved stability in PeLED devices.

Main Methods:

• Composition and phase engineering of Formamidinium (FA)-based perovskites.
• Incorporation of low-dimensional FA₂PbBr₄ particles into FAPbBr₃ composites.
• Optimization of film quality and emission efficiency using Rb⁺ ions.

Main Results:

• Regulating phase composition in multiphase FAPbBr₃ perovskites increased maximum external quantum efficiency (EQE_max) to 5.14% (2.7-fold higher than pure FAPbBr₃).
• Device stability was significantly improved.
• Further optimization with Rb⁺ ions yielded an EQE_max of 6.01% and a half-lifetime of ~185 s under high current density.

Conclusions:

• Phase composition optimization is an effective strategy for developing high-efficiency and stable FA-based PeLEDs.
• The study demonstrates a pathway to overcome limitations in current perovskite optoelectronic devices.
• Engineered perovskite materials offer potential for advanced light-emitting applications.