The CdSe-based quantum dots (QDs) have been applied to light-conversion nano-phosphors due to tunable emission and pure colors. However, these cadmium-containing QDs was strongly toxic and synthesized in a hazardous solvent. In addition, conventional QD nano-phosphors with a small Stokes shift suffered from reabsorption losses and aggregation-induced photoluminescence (PL) quenching in the solid state. Therefore, there is a need to develop nanophosphors with a large Stokes shift. Here, we demonstrate one-pot synthesis of gold nanoclusters (AuNCs) using 3- aminopropyltrimethoxysilane (APS) and glutathione as protection ligand with a large Stokes shift. The gold nanoclusters with a large Stokes shift can mitigate the aggregation-induced PL quenching and reabsorption losses, which would be potential candidates for "green" nano-phosphors.
Heavy-metal-containing quantum dots (QDs), such as CdSe-based quantum dots (QDs) have been applied to lightconversion nano-phosphors due to tunable emission and pure colors. Unfortunately, those QDs involve toxic elements and synthesize in a hazardous halogenated solvent. Therefore, Eco-friendly gold nano-clusters (AuNCs@GSH) in solution phase have gained much attention for promising applications in biophotonics. For the first time, we explore the feasibility of aqueous-solution-processed AuNCs@GSH as luminescent species for promising applications in "green" luminescent solar concentrators (LSCs) by investigating their photophysical properties. Due to ligand-to-metal chargetransfer (LMCT) state, we found that such "green" LSCs formed by Zn-AuNCs@GSH dispersed in a polymer matrix exhibit large Stokes shift and small scattering losses. Compared to AuNCs@GSH, the Zn-AuNCs@GSH dispersed in a polymer matrix could suppress non-radiative recombination rates, inducing the enhancement of luminescence and the increase of PL-QY from 2% to 40%.
The photoluminescence (PL) properties in GaN epilayers were investigated after depositing graphene quantum
dots (GQDs) on the GaN surface. A seven-fold enhancement of the PL intensity in GaN was observed in the GQD/GaN
composite. On the basis of the PL dynamics, the enhancement of PL in GaN is attributed to the carrier transfer from
GQDs to GaN. Such a carrier transfer is caused by the work function difference between GQDs and GaN, evidencing by
Kelvin probe measurement. The improved PL is promising toward applications in the GaN-based optoelectronic devices.