Pyridine-Derived Multifunctional Additive Enabling Highly Efficient Perovskite Light-Emitting Diodes

Area of Science:

• Materials Science
• Optoelectronics
• Chemical Engineering

Background:

• Benzene derivatives are common additives for passivating defects in perovskite light-emitting diodes (PeLEDs).
• Steric hindrance in benzene derivatives limits their effectiveness and durability due to detachment from perovskites.
• Developing new additives is crucial for improving PeLED performance and longevity.

Purpose of the Study:

• To introduce a novel pyridine-based additive, 3-pyridinylmethylammonium cation (3-pyA+), for enhanced perovskite passivation in PeLEDs.
• To investigate the synergistic passivation effect of pyridine and ammonium groups in 3-pyA+.
• To compare the performance and stability of PeLEDs using 3-pyA+ with those using traditional benzene derivatives.

Main Methods:

• Incorporation of 3-pyA+ additive into perovskite films.
• Fabrication of green PeLEDs using 3-pyA+-treated and phenylmethanamine cation (PMA+)-treated perovskite films.
• Characterization of film properties, including crystallinity and photoluminescence quantum yield (PLQY).
• Evaluation of device performance, including external quantum efficiency (EQE) and operational stability (T50).

Main Results:

• 3-pyA+ additive promotes the formation of uniform perovskite films with enhanced crystallinity.
• Perovskite films treated with 3-pyA+ showed a significant increase in PLQY from 73% to 92%.
• 3-pyA+-treated PeLEDs achieved a peak EQE of 30.8%, outperforming PMA+-treated devices (22.5%).
• Device stability (T50) improved from 50 to 200 minutes for 3-pyA+-treated PeLEDs.

Conclusions:

• The pyridine-based 3-pyA+ additive offers superior passivation effects for perovskite defects compared to benzene derivatives.
• Dual-site binding of pyridine and ammonium groups in 3-pyA+ enhances film quality, efficiency, and durability of PeLEDs.
• 3-pyA+ represents a promising strategy for developing high-performance and stable perovskite optoelectronic devices.