Plasmonic Gold Nanorods Coverage Influence on Enhancement of the Photoluminescence of Two-Dimensional MoS2 Monolayer

Abstract

The 2-D transition metal dichalcogenide (TMD) semiconductors, has received great attention due to its excellent optical and electronic properties and potential applications in field-effect transistors, light emitting and sensing devices. Recently surface plasmon enhanced photoluminescence (PL) of the weak 2-D TMD atomic layers was developed to realize the potential optoelectronic devices. However, we noticed that the enhancement would not increase monotonically with increasing of metal plasmonic objects and the emission drop after the certain coverage. This study presents the optimized PL enhancement of a monolayer MoS2 in the presence of gold (Au) nanorods. A localized surface plasmon wave of Au nanorods that generated around the monolayer MoS2 can provide resonance wavelength overlapping with that of the MoS2 gain spectrum. These spatial and spectral overlapping between the localized surface plasmon polariton waves and that from MoS2 emission drastically enhanced the light emission from the MoS2 monolayer. We gave a simple model and physical interpretations to explain the phenomena. The plasmonic Au nanostructures approach provides a valuable avenue to enhancing the emitting efficiency of the 2-D nano-materials and their devices for the future optoelectronic devices and systems.

Photoluminescence enhancement of monolayer MoS2 using plasmonic gallium nanoparticles

“…50 The shi between the two main peaks is a common tool to determine the number of layers in MoS 2 akes. 20,51 Monolayer MoS 2 exhibits a frequency difference of 20 cm À1 between the two modes, as in our case. The sharp peak in the as-grown sample around 415 cm À1 is due to the Raman signal of sapphire.…”

“…In fact, plasmonics and 2D materials have been actively investigated during the last few years. [16][17][18] However, until now, only silver (Ag) and gold (Au) NPs have been used for the PL enhancement of MoS 2 8,[18][19][20][21][22][23][24] due to their low losses in the VIS range 25,26 compared to the so-called poor metals that have their main activity in the ultraviolet (UV) region such as aluminum (Al), magnesium (Mg), rhodium (Rh), indium (In) and gallium (Ga). 27 In particular, Ga has been previously shown to facilitate light-matter interaction in a wide variety of applications such as biosensors, 28,29 solid-liquid phase-change memories, 30 waveguiding 31 and surface enhanced Raman scattering (SERS) in the VIS 32 and the UV 33 region.…”

Plasmonics of 2D Nanomaterials: Properties and Applications

“…The electric field contributes to the strength of light‐matter interaction resulting in absorption enhancement 109, 110, 111, 112. Excited electrons of 2D semiconductors are generated from light absorption, then relax to the bottom of conductance band, bind into exciton energy level, and finally decay in relaxation process which includes non‐radiative and radiative decay.…”

Controlling plasmon-exciton interactions through photothermal reshaping

“…Plasmon-exciton hybrids, as platforms for investigating light-matter interactions with various mechanisms such as plasmon-induced resonance energy transfer (RET) 1,2 , Fano interference [3][4][5] , strong coupling [6][7][8][9][10][11][12] , and plasmon-enhanced absorption and emission [13][14][15][16][17][18][19][20][21][22][23] have attracted much attention. Monolayer transition metal dichalcogenides (TMDCs) have evoked strong interests owing to their fascinating optical properties and flexible features for integration 24 .…”