Perovskite Light-Emitting Diodes with External Quantum Efficiency Exceeding 22% via Small-Molecule Passivation

Area of Science:

• Materials Science
• Optoelectronics
• Solid-State Chemistry

Background:

• Perovskite light-emitting diodes (PeLEDs) offer excellent color expression for displays and lighting.
• Polycrystalline perovskite films often contain defects that hinder performance.
• Mitigating non-radiative recombination defects is key to enhancing PeLED efficiency.

Purpose of the Study:

• To introduce a novel passivation strategy for perovskite films.
• To improve the efficiency and stability of green PeLEDs.
• To explore the use of ethoxylated trimethylolpropane triacrylate (ETPTA) as a defect passivating agent.

Main Methods:

• ETPTA was dissolved in an antisolvent and used during the perovskite film spinning process.
• The additive passivated surface and bulk defects in the perovskite films.
• Device performance metrics including external quantum efficiency (EQE) and operational stability (T50) were evaluated.

Main Results:

• ETPTA effectively passivated defects, reducing charge trapping states.
• Perovskite films treated with ETPTA achieved a maximum external quantum efficiency (EQE) of 22.49%.
• A threefold increase in the operational lifetime (T50) was observed compared to control devices.

Conclusions:

• ETPTA provides a simple and effective method for creating highly efficient perovskite films.
• This strategy significantly enhances the performance of green PeLEDs.
• The findings pave the way for improved perovskite-based optoelectronic devices.