Manipulating Structural Asymmetry in FAPbBr3 Quantum Dots for High-Performance Pure-Green Spin-Polarized...

Area of Science:

• Materials Science
• Quantum Dot Technology
• Optoelectronics

Background:

• Spin-polarized light-emitting diodes (spin-LEDs) offer direct circularly polarized electroluminescence for advanced photonic applications.
• Perovskite quantum dots (QDs) are promising materials for optoelectronic devices, but their performance needs enhancement.

Purpose of the Study:

• To engineer high-performance pure-green spin-LEDs using FAPbBr3 quantum dots.
• To investigate the effect of chiral ligand engineering on the optoelectronic properties and spin characteristics of FAPbBr3 QDs.

Main Methods:

• A multifunctional chiral ligand engineering strategy using (R/S)-methylbenzenesulfinamide was employed.
• This strategy involved coordinating the ligand with surface Pb2+ ions in FAPbBr3 QDs to passivate defects and induce lattice distortion.
• Characterization of chiroptical activity, spin-coherence lifetimes, and optoelectronic performance of the modified QDs and fabricated spin-LEDs.

Main Results:

• Chiral FAPbBr3 QDs exhibited enhanced chiroptical activity and prolonged spin-coherence lifetimes.
• Achieved a high photoluminescence quantum yield of 98.28% and a large dissymmetry factor of 8.87 × 10-2.
• Fabricated spin-LEDs demonstrated pure-green emission with high luminance (17,979 cd m-2), peak external quantum efficiency (15.1%), and electroluminescence dissymmetry factor (1.76 × 10-1).

Conclusions:

• Multifunctional chiral ligand engineering is an effective strategy for improving perovskite quantum dot optoelectronic quality and introducing structural asymmetry.
• This approach leads to high-performance pure-green spin-LEDs with potential for practical applications in next-generation photonic technologies.