Highly Enhanced Photoluminescence of Monolayer MoS₂ in Plasmonic Hybrids with Double-Layer Stacked Ag Nanoparticles

Abstract

In this work, a feasible method was proposed to prepare MoS 2 -based plasmonic hybrid systems with high photoluminescence (PL) emission enhancement. The enhancement effect of plasmonic hybrids on the PL emission of MoS 2 has been systematically studied on MoS 2 /Ag spherical nanoparticle (SP) hybrid systems with different architectures by changing the stacking position of Ag SPs. It is demonstrated that the sandwich-like hybrid composed of monolayer MoS 2 and dielectric Al 2 O 3 layer between two layers of Ag SPs has the highest PL enhancement. Remarkably, after adding an Al 2 O 3 layer under MoS 2 , the PL intensity enhancement up to 209 times was achieved in the sandwich-like hybrid system. Compared with the hybrid with single-layer SPs, the sandwich-like hybrid system with double-layer Ag SPs exhibited an obvious blue shift as a result of the selective enhancement of the A 0 exciton in MoS 2 . These results demonstrate that MoS 2 /Ag SP hybrid nanosystems have significant implications for sensing and photoelectronic devices.

Charge Mobility and Strain Engineering in Two-Step MS-Grown MoS2/Seed Layer Heterointerface and Photo-Excitation Mechanism

“…Singh et al reported a trion formation time of about 2 ps for MoSe 2 , which is in good agreement with our experimental data. 62 The formation of charged excitons in MoS 2 on metallic Ag is detected possibly due to the coupled oscillation of the plasmon around the metal with the excitons in MoS 2 , which increases the probability of the formation of charged excitons under photo-excitation (see process II in Figure 6i). 63 The slow relaxation time component that occurs on ZnO, Al 2 O 3 , and Ag substrates is attributed to the exciton−exciton annihilation or Auger recombination that occurs when electrons return from the conduction band to the valence band (see the purple part (8.35, 13.41 × 10, and 14.79 × 10 ps) in Figure 6h) (see process I in Figure 6i).…”

Simple Fabrication of Photodetectors Based on MoS2 Nanoflakes and Ag Nanoparticles

“…It has been reported that the Ag NPs can be attached to the MoS 2 surface via the formation of the Ag ions in the solution [34], and the MoS 2 layer can play a role as a photocatalyst with the Ag NPs [15]. Notably, the surface plasmon resonance effect of metal NPs can increase visible light absorption [35,36]. Surface plasmons can be localized by Ag NPs, and the excitation of localized surface plasmon resonance can occur.…”

Au–WS2 Nanohybrids with Enhanced Optical Nonlinearity for Optical Limiting Applications

“…Recently, nanoengineering has shown a tremendous impact in overcoming these issues by providing breakthrough solutions to achieve better tunability in intrinsic properties of materials. , The development of quantum-confined structures, such as nanowires, nanosheets, nanoparticles (NPs), nanodots, and so forth, helps in improving the applicability of these materials. − Most of the modern optoelectronic devices, such as light-emitting diodes, solar cells, photodetectors, and nonlinear-optical devices, based on inorganic semiconducting nanostructures provide superior performance in terms of both efficiency and stability. − To further enhance the multifunctionality and practicality of these new class of materials, intrinsic properties need to be tuned precisely according to their targeted applications. For this purpose, researchers have integrated semiconductor nanostructures with metal nanostructures and developed metal–semiconductor nanohybrid systems with promising optoelectronic properties. − These nanohybrid materials provide excellent tunability in optoelectronic properties via simple modifications on the material composition and their physical dimensionality . Moreover, metal–semiconductor nanohybrids combine advantages of constituent metals and semiconductors and act as high potential platforms to meet critical scientific needs for a variety of applications.…”