Photoluminescence quenching in gold - MoS2 hybrid nanoflakes

Abstract

Achieving tunability of two dimensional (2D) transition metal dichalcogenides (TMDs) functions calls for the introduction of hybrid 2D materials by means of localized interactions with zero dimensional (0D) materials. A metal-semiconductor interface, as in gold (Au) - molybdenum disulfide (MoS2), is of great interest from the standpoint of fundamental science as it constitutes an outstanding platform to investigate plasmonic-exciton interactions and charge transfer. The applied aspects of such systems introduce new options for electronics, photovoltaics, detectors, gas sensing, catalysis, and biosensing. Here we consider pristine MoS2 and study its interaction with Au nanoislands, resulting in local variations of photoluminescence (PL) in Au-MoS2 hybrid structures. By depositing monolayers of Au on MoS2, we investigate the electronic structure of the resulting hybrid systems. We present strong evidence of PL quenching of MoS2 as a result of charge transfer from MoS2 to Au: p-doping of MoS2. The results suggest new avenues for 2D nanoelectronics, active control of transport or catalytic properties.

Plasmonic Pumping of Excitonic Photoluminescence in Hybrid MoS2–Au Nanostructures

“…Moreover, it is well known that PL emission could be quenched when the emitter is in the close vicinity of the plasmonic resonator. 20 Moreover, Bhanu et al 21 have recently shown that the photoluminescence of MoS 2 flakes is strongly quenched upon Au deposition as a result of charge transfer from MoS 2 to Au. However, since in our experiments a PL enhancement of about 65% is measured ( Figure 3B), we can conclude that increased optical absorption into the MoS 2 overpasses the PL quenching.…”

Growth of WS2 flakes on Ti3C2Tx Mxene Using Vapor Transportation Routine

“…Auger recombination at WS 2 /Ti 3 C 2 T x interface is the first possible reason quenching the PL intensity of TT4. The PL intensity of MoS 2 can be greatly quenched at MoS 2 /graphene [32] and MoS 2 /Au [33] contact due to strong Auger recombination. The electric conductivity of Ti 3 C 2 T x is 4.2 × 10 −4 S/m [9], which is comparable to graphene.…”

Discrete quantum dot like emitters in monolayer MoSe2: Spatial mapping, magneto-optics, and charge tuning

“…Remarkably, the 2D exciton emission is not spectrally shifted (within a few meV) compared to samples exfoliated onto SiO 2 /Si and the trion binding energy of E 2D-X0 PL À E 2D-XT PL % 31 meV is not influenced by the choice of metal substrate. Also, for the related ML material MoS 2 , it has been reported that the emission of the direct gap 2D excitons is little affected by the gold substrate, 41,42 presumably due to the very small exciton Bohr radius in ML TMDs. 43,44 The exact ratio of the PL intensities 2D-XT: 2D-X0 varies across the sample, compare in Fig.…”