| Περίληψη |
Transition metal dichalcogenides (TMDs) are semiconductors consisting of a transition metal
and two chalcogen atoms. They have a chemical type of MX2 where M is a transition metal and
X a chalcogen atom. They are part of a larger group known as 2D materials named so to
emphasize their extraordinary thickness, which is at the order of some Å. In their monolayer
form, TMDs have a direct bandgap and this makes them ideal for their use in various applications
in valleytronics, electronics (as transistors) and in optics (as photoemitters and detectors).
Therefore, monolayer TMDs have received significant attention. Monolayer Molybdenum
disulfide (MoS2) in particular, gains considerable attention due to its direct band gap and
potential integration with other nanostructures to form nanoscale van der Waals heterojunctions
with intriguing physical and optical properties. Indeed, several studies have been carried out for
an attempt to enhance and control the optical properties of the monolayer (mostly) and few
layers MoS2. For example, Catalan-Gomez et al. used MoS2 monolayers and Ga nanoparticles
(NPs) in a attempt to enhance the photoluminescence (PL) of the 2D material, J.Yan et al. used
few-layered MoS2 and Au NPs with the aim of controlling the PL of MoS2 by controlling the size
and aggregation of the Au NPs in various spots, X. Zhang et al. used MoS2 monolayers and
photonic crystals in an attempt to also enhance the PL of MoS2 and J. Huang et al. utilized silver
nanotubes on monolayer MoS2 to control the A and B exciton emissions. A major breakthrough
achieved by Abdus S. Sarkar et al. at ULMNP labs at FORTH, when they embedded few-layered
MoS2 flakes into a sliver metaphosphate (AgPO3) glass matrix. Indeed, they achieved a
remarkable enhancement of both A and B exciton emissions at room temperature. It has been
also demonstrated by the same group at ULMNP the ability to create laser induced periodic
surface structures (LIPSS) on a AgPO3 matrix. It is well known that the excitons in TMDs can
interact with plasmonic profiles of metal NPs of various dimensionalities and this can increase
the PL of a material. It is also known that when strain is applied on a material, I can change the
internal band structure of that material and this has an effect on its optical properties.
The aim of this project is to shed light on how the PL properties of few-layered MoS2 would change
when a plasmon-exciton coupling is combined with a strain profile applied on the 2D material
using LIPSS.
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Development of composite 2D material-glasses (MoS2 -glasses) for optoelectronics applications
