Enhanced Multiphoton Emission from CdTe/ZnS Quantum Dots Decorated on Single-Layer Graphene

Abstract

Time-resolved single-molecule spectroscopy of individual colloidal CdTe/ZnS quantum dots (QDs) decorated on single-layer graphene (SLG) demonstrates significantly enhanced probability of multiphoton emission, accompanied by reduced fluorescence intensity and decreased lifetime. A rigorous analysis of time-resolved spectroscopy on individual QDs on SLG reveals a decrease in radiative decay rate and a significant enhancement (12.6 times) in nonradiative decay rate. The enhanced multiphoton emission of QDs on SLG is a consequence of the competition between the enhanced nonradiative decay and fast Auger process, as suggested by the dominant fast decay (<0.8 ns) of QDs on SLG. Our findings provide important information on the emission behavior of QDs coupled with carbon nanomaterials, such as graphene and carbon nanotubes, and will assist in the creation of effective single-photon or multiphoton sources and devices. Furthermore, this is also a possible pathway for suppressing the Auger recombination of QDs while enhancing the generation of multicarriers, which has significant implications for light harvesting.

Single-molecule tracking in liveYersinia enterocoliticareveals distinct cytosolic complexes of injectisome subunits

“…It is therefore possible that the D ~ 1 µm 2 /s diffusive state observed in our work is due to the cytosolic presence of a large supramolecular complex that contains six SctK-Q-L pods, which are each connected to a central hexameric ATPase. Such a supramolecular complex would have a molecular weight of ~2 MDa, assuming previously estimated stoichiometries (9,10,20,21,28), and could form either through the stepwise assembly in the cytoplasm or upon concerted dissociation from membraneembedded injectisomes. An alternative explanation is that the D ~ 1 µm 2 /s diffusive state represents a single pod that is connected to SctL and possibly SctK and SctN.…”

“…The precise positions of the sorting platform proteins SctK, SctQ, SctL, and the ATPase SctN within the in situ quaternary structure of fully assembled injectisomes have recently been determined by cryo-electron tomography (9)(10)(11). The 3D tomogram averages reveal a cytoplasmic injectisome complex of hexametric symmetry, which is notably different from the continuous cytoplasmic ring (C-ring) structure observed in flagellar T3SSs (22)(23)(24).…”

“…The recognition and selection of export substrates is hypothesized to result from coordinated interactions among the cytoplasmic components of the injectisome, which attach to the membrane-embedded rings of the injectisomes ( Fig. 1) (9)(10)(11).…”

Laser Shock Tuning Dynamic Interlayer Coupling in Graphene–Boron Nitride Moiré Superlattices

“…When QDs are transferred to graphene ( Fig. 4(b)), it shows the strong carrier transfer from the QDs to the graphene due to its zero bandgap nature, to enhance the nonradiative decay rate of the QD by more than 10 times [24][25][26][27] .…”

Enhanced terahertz emission from quantum dot by graphene-coated nanoparticle

“…One such possibility is to employ graphene plasmonics [6], which has been intensively studied by many researchers in the literature due to the unique properties in the collective motion of the p electrons in the graphene [7,8]. Moreover, a recent investigation employing planar single-layer graphene for the enhancement of CdTe/ZnS QD emission has reported only multiphoton emission enhancement, with fluorescence intensity actually reduced due to the decrease in QD radiative decay rate in the proximity of the graphene [9]. Nevertheless, there exist other graphene nano-structures which may effect differently on their plasmonic enhancement of QD emissions.…”