Review Reports

Round 1

Reviewer 1 Report

I understand the relevance of the topic. I understand that a lot of work has been done in order to fabricate these materials. However I fail at understanding if there is any novelty. The study presents some basic characterisation of the fabricated material.

As a suggestion, measuring the optical transmittance with an out-of-plane polarized light (illumination under oblique incidence) could bring a more visible interaction between the two components of the hybrid system.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

In this manuscript the authors present an interesting analysis on the optical response of CVD-grown ML-WS2 flakes on an ultra-dense Au NP plasmonic array. The manuscript is clear, well organized and nicely presented.

I have only small suggestions before the acceptance:

• Since the LSPR peak is highly influenced by the shape and size of the gold nanoparticles, how much are these parameters important in this kind of analysis?
• Regarding the hybrid system, in Figure 2c are shown the micro-absorbance spectra as a function of the LiF dielectric thickness (t). Can the authors give more detail on why the LSPR peak fades at increasing t?
• I would also suggest to change the color of the spectra in Figure 2 since the ones related to t=0nm and t=3nm are not distinguishable.
• Some typos are present in the text, please check.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

In the manuscript, the authors prepared a hybrid system of monolayer WS₂ flakes grown by chemical vapour deposition and ML-WS₂ on a densely-packed array of Au nanoparticles, and investigated the optical properties of ML-WS₂ flakes and ML-WS₂ on Au NPs. In the 75-350 K range, the optical response was measured as a function of the thickness of a dielectric spacer intercalated between the two materials and of the system temperature of ML-WS₂ and ML-WS₂ /Au NPs. The idea of the manuscript seems applicable. There are some issues that need to be addressed:

Point 1: The closely-packed array of the plasmonic Au nanoparticles promotes a high confinement of the electromagnetic field, whether it can be illustrated by electric field distribution diagram?

Point 2: The increasing of thickness of the intercalated LiF layer will lead to a gradual redshift of the LSPR in Figure 2 (b), the author should discuss and add the physical mechanism.

Point 3: What are the practical applications of the hybrid system of monolayer WS₂  and ML-WS₂ on a densely-packed array of Au nanoparticles?

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

I think the article can be accepted now.

Author Response

Dear Reviewer,

thank you for your reply.

With best regards,

on behalf of all co-authors,

Marzia Ferrera and Francesco Bisio