Delayed luminescence guided enhanced circularly polarized emission in atomically precise copper nanoclusters

Area of Science:

• Materials Science
• Nanotechnology
• Physical Chemistry

Background:

• Metal nanoclusters are known for unique optical properties.
• Chiral nanoclusters exhibiting optical activity are of significant research interest.
• Focus is shifting towards understanding excited-state chirality in nanoclusters.

Purpose of the Study:

• To synthesize and investigate enantiomerically pure copper nanoclusters.
• To explore their ground- and excited-state chiral optical properties.
• To establish structure-property correlations for these chiral nanoclusters.

Main Methods:

• Synthesis of copper nanoclusters using chiral ligands (l- and d-isomers).
• Chiroptical analysis including circular dichroism and circularly polarized luminescence.
• Structural characterization using single crystal XRD, powder XRD, and XPS.
• Computational analysis and photoluminescence mechanism investigations.

Main Results:

• Successfully synthesized enantiomerically pure copper nanoclusters with intense optical activity.
• Observed mirror-image circular dichroism and circularly polarized luminescence signals.
• Demonstrated circularly polarized delayed luminescence due to long excited-state lifetimes and chirality.
• Established a unique structure-property correlation for these copper nanoclusters.

Conclusions:

• The synthesized copper nanoclusters exhibit significant ground- and excited-state chirality.
• Circularly polarized delayed luminescence is a key characteristic of this system.
• These chiral nanoclusters show potential for applications in data encryption, security tags, and polarized light emitting devices.
• Understanding excited-state chirality in copper clusters opens new research avenues for other metal clusters.