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

Area of Science:

• Materials Science
• Optoelectronics
• Solid-State Physics

Background:

• Perovskite light-emitting diodes (PeLEDs) offer excellent color expression but suffer from defects in polycrystalline films, limiting performance.
• Non-radiative recombination defects in perovskite materials are a major obstacle for high-efficiency light-emitting applications.

Purpose of the Study:

• To introduce ethoxylated trimethylolpropane triacrylate (ETPTA) as a passivation agent for perovskite films.
• To mitigate surface and bulk defects in perovskite films during the fabrication process.
• To enhance the efficiency and operational stability of PeLEDs.

Main Methods:

• ETPTA was dissolved in an antisolvent and used to passivate perovskite films during the spinning process.
• The effect of ETPTA on charge trapping states and defect reduction was investigated.
• The performance of PeLED devices fabricated with ETPTA-passivated films was evaluated.

Main Results:

• ETPTA effectively passivated surface and bulk defects, reducing charge trapping states.
• Perovskite films passivated with ETPTA yielded PeLEDs with a maximum external quantum efficiency (EQE) of 22.49%.
• A threefold increase in the T50 operational time was observed for devices treated with ETPTA compared to control samples.

Conclusions:

• ETPTA is a simple and effective additive for creating highly efficient perovskite films.
• This strategy significantly improves the performance and stability of perovskite light-emitting diodes.
• The findings present a promising approach for advancing perovskite optoelectronics.