Periodic Fluorescence Variations of CdSe Quantum Dots Coupled to Aryleneethynylenes with Aggregation Induced Emission

TL;DR

This study investigates the periodic fluorescence variations in a hybrid material composed of CdSe quantum dots and aryleneethynylene derivatives, revealing structure-dependent aggregation induced emission and its effects on energy transfer and electrical properties.

Contribution

It demonstrates the novel phenomenon of anti-correlated, periodic fluorescence in hybrid nanocrystal-molecule systems driven by aggregation induced emission effects.

Findings

Periodic fluorescence variations observed at low temperature.

Aggregation induced emission influences energy transfer rates.

Hybrid material exhibits unique optical and electrical properties.

Abstract

CdSe nanocrystals and aggregates of an aryleneethynylene derivative are assembled into a hybrid thin film with dual fluorescence from both fluorophores. Under continuous excitation, the nanocrystals and the molecules exhibit anti-correlated fluorescence intensity variations, which become periodic at low temperature. We attribute this to a structure-dependent aggregation induced emission of the aryleneethynylene derivative, which impacts the rate of excitation energy transfer between the molecules and nanocrystals. Energy transfer also affects the electric transport properties of the hybrid material under optical excitation. This work highlights that combining semiconductor nanocrystals with molecular aggregates, which exhibit aggregation induced emission, can result in unprecedented emerging optical properties.