Distance makes a difference in crystalline photoluminescence

Area of Science:

• Nanochemistry
• Materials Science
• Photophysics

Background:

• Ultrasmall metal nanoparticles exhibit crystallization-induced photoluminescence weakening.
• The underlying mechanisms of this phenomenon remain poorly understood.

Purpose of the Study:

• To investigate the fundamentals of crystallization-induced photoluminescence weakening in gold nanoclusters.
• To propose and validate a model explaining the observed photoluminescence changes.

Main Methods:

• Synthesis of conformational isomer crystals of gold nanoclusters.
• Photoluminescence spectroscopy.
• High-pressure photoluminescence experiments.
• Theoretical modeling of electron transfer.

Main Results:

• Shortening of interparticle distance in crystallized gold nanoclusters leads to decreased photoluminescence.
• High-pressure experiments confirm the effect of interparticle distance on photoluminescence.
• A distance-dependent non-radiative transfer model for excitation electrons was proposed and supported by data.
• The model successfully explains both aggregation-induced quenching and emission.

Conclusions:

• Crystallization-induced photoluminescence weakening in gold nanoclusters is attributed to distance-dependent non-radiative electron transfer.
• This research advances the understanding of photoluminescence in aggregated nanomaterials.
• The study highlights the significance of conformational isomerism and high-pressure techniques in nanochemistry.