Competition Between Resonant Plasmonic Coupling and Electrostatic Interaction in Reduced Graphene Oxide Quantum Dots

Abstract

The light emission from reduced graphene oxide quantum dots (rGO-QDs) exhibit a significant enhancement in photoluminescence (PL) due to localized surface plasmon (LSP) interactions. Silver and gold nanoparticles (NPs) coupled to rGO nanoparticles exhibit the effect of resonant LSP coupling on the emission processes. Enhancement of the radiative recombination rate in the presence of Ag-NPs induced LSP tuned to the emission energy results in a four-fold increase in PL intensity. The localized field due to the resonantly coupled LSP modes induces n-π* transitions that are not observed in the absence of the resonant interaction of the plasmons with the excitons. An increase in the density of the Ag-NPs result in a detuning of the LSP energy from the emission energy of the nanoparticles. The detuning is due to the cumulative effect of the red-shift in the LSP energy and the electrostatic field induced blue shift in the PL energy of the rGO-QDs. The detuning quenches the PL emission from rGO-QDs at higher concentration of Ag NPs due to non-dissipative effects unlike plasmon induced Joule heating that occurs under resonance conditions. An increase in Au nanoparticles concentration results in an enhancement of PL emission due to electrostatic image charge effect.

A High Energy Density Azobenzene/Graphene Oxide Hybrid with Weak Nonbonding Interactions for Solar Thermal Storage

“…3(a) ) shows a peak at 284.6 eV, corresponding to sp 2 carbon framework in a conjugated honey-comb. Three components centered at 286.4 eV, 287.1 eV and 288.7 eV are related to C-OH, C-O-C (epoxy and alkoxy), and C=O groups, respectively, which are in good agreement with the previous reports 21 , 22 . For RGO (Fig.…”

“…The deconvolution of each C 1s spectrum has been summarized in Table 1 . According to XPS spectrum, it is found that the C/O ratio is 2.96 for GO, indicating a high oxygen atomic percentage in the as-prepared GO though it is a high-bound estimate for the real value 19 , 21 . The C 1s core level XPS of GO (Fig.…”

Plasmonically-powered hot carrier induced modulation of light emission in a two-dimensional GaAs semiconductor quantum well

“…However, in the presence of the GaNPs, the attraction of the electron and hole leads to the electrostatic effect which results in an image charge induced Stark effect. 29,31 As the image charge results in a Coulomb attraction of the carriers, the force of the attraction depends on the location of the charge carriers with respect to its distance from the metal nanoparticles. It results in a modification of the alignment of the conduction band and valence band line-up with respect to the spatial distance along the z-direction (growth direction) due to its difference in the distance from the Ga nanodroplet surface.…”

“…A higher concentration of metal nanoparticles around a plasmonic emitter can be detrimental to the plasmonically enhanced light emission process as the plasmon frequency can be detuned away from the light emission energy. 31 Moreover, single-species metal nanoparticle plasmon systems have one specific bandwidth of plasmon frequency. The presence of an additional plasmon species to a plasmonic light emitter can enable the stimulation of hot carrier generation and photoexcited carrier density modulation.…”

Reduced graphene oxide modified with silver nanoparticles for the electrochemical detection of estriol

“…It should be noted that the HOMO energy level presented in the Fig. 6 corresponds to the average HOMO energy for all structures obtained from the MD simulations at temperature of 300 K. The values of work function of the rGO/AgNPs were obtained from the literature, in which a large range of values are related, depending of the Ag nanoparticles size and concentration [43][44][45][46][47].…”