Lattice-matched molecular-anchor design for high-performance perovskite quantum dot light-emitting diodes

Area of Science:

• Materials Science
• Optoelectronics
• Nanotechnology

Background:

• Perovskite quantum dots (QDs) offer high external quantum efficiencies (EQEs) exceeding 25% in light-emitting diodes (LEDs).
• Limited operating stability due to surface defects and ion migration hinders practical applications of perovskite QD LEDs.

Purpose of the Study:

• To design a novel anchoring molecule for stabilizing perovskite QDs.
• To enhance the operational stability and performance of perovskite QD-based LEDs.

Main Methods:

• Synthesized tris(4-methoxyphenyl)phosphine oxide (TMeOPPO-p) as a lattice-matched anchoring molecule.
• Anchored multi-site defects and stabilized the perovskite QD lattice using TMeOPPO-p.
• Fabricated and characterized perovskite QD LEDs.

Main Results:

• Achieved near-unity photoluminescence quantum yields (97%) in target QDs.
• Demonstrated maximum EQE of 27% at 693 nm in fabricated QD LEDs.
• Exhibited low efficiency roll-off (>20% at 100 mA cm⁻²) and an operating half-life exceeding 23,000 hours.
• Air-processed devices maintained EQE >26% with good storage stability.

Conclusions:

• TMeOPPO-p effectively anchors defects and stabilizes the perovskite QD lattice.
• The developed molecule significantly enhances the stability and performance of perovskite QD LEDs.
• This work provides a pathway for rational molecular design for perovskite QDs in optoelectronics.