Polarization-Dependent Light Emission and Charge Creation in MoS₂ Monolayers on Plasmonic Au Nanogratings

Abstract

We fabricated plasmonic hybrid nanostructures consisting of MoS 2 monolayer flakes and Au nanogratings with a period of 500 nm. The angle-resolved reflectance and photoluminescence spectra of the hybrid nanostructures clearly indicated a coupling between surface plasmon polaritons (SPPs) and incoming photons. The surface photovoltage (SPV) maps could visualize the spatial distribution of net charges while shining light on the sample. Considerable polarization and wavelength dependence of the SPV signals suggested that the SPP mode enhanced the light−matter interaction and resulting exciton generation in the MoS 2 monolayer. From the photoluminescence spectra and the morphology of the suspended MoS 2 region, it could be noted that light irradiation did not much raise the temperature of the MoS 2 monolayers on the nanogratings. Nanoscopic SPV and surface topography measurements could reveal the local optoelectronic and mechanical properties of MoS 2 monolayers. This work provided us insights into the proposal of a high-performance MoS 2 /metal optoelectronic devices, based on the understanding of the SPP−photon and SPP−exciton coupling.

Photoluminescence of MoS2 on Plasmonic Gold Nanoparticles Depending on the Aggregate Size

“…Since the resulting low photocurrent and photoluminescence (PL) restrict the overall performance of the device, the practical application of TMDs is inefficient. As a promising strategy for reducing absorption loss, combining TMDs with nanophotonic devices, such as meta- − and plasmonic − structures, has garnered significant attention. The heterohybrid structures have the potential to offer new functionalities and exploit synergistic effects through material interactions, which can highly improve the device performance and control the optical, electronic, and electrical properties.…”

Enhanced optical absorption in conformally grown MoS2 layers on SiO2/Si substrates with SiO2 nanopillars with a height of 50 nm

“…The samples with suspended region also have stability issues. 7 Incident light can raise the sample temperature, which can induce mechanical stress to the TMDC layers owing to the difference in the thermal expansion coefficients. 17,18 If the morphology of the suspended region is changed during repeated optical measurements, reproducible data are hard to obtain.…”