Optimizing Crystalline MoS2 Growth on Technologically Relevant Platinum Substrates Using Ionized Jet Deposition: Interface Interactions and Structural Insights
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThis research study has been well conducted and the results are interesting, but some modification must be addressed before the paper can be accepted for publication.
It would be necessary to introduce the supplementary material in the paper, with some structural modifications, as follows:
- At the end of the Introduction (lines 77-86), refer also to the SEM and AFM results
- Section 2 (Materials and Methods) should be reorganized as follows:
- 2.1. IJD System Upgrade - adding the corresponding paragraph and figures from the Supplementary material
- 2.2. Thin Film Growth
- 2.3. Characterization methods – add the description of SEM and AFM equipments/methods
- 3 Results and discussion
Add the supplementary material and renumbering the figures.
3.1 Structural and Morphological Characterization (XRD, SEM, TEM, AFM, Raman)
- figure 1 should be split in two by separating the TEM images. If there is selected area electron diffraction (SAED) data to add to the discussion between XRD and TEM
- add from the supplementary material the AFM and SEM results with cross-section SEM images useful for the multilayer vs interface(s) discussion.
3.2. Chemical Characterization (XPS, UPS)
The central point of the paper is the XPS analysis being a continuation of the study of optimizing the crystalline growth of MoS2 on different substrates using ion beam deposition. A table should be included with the binding energies of the data regarding the Pt and SiO2/Si substrates [references 15, 17]
The UPS results should be also presented in the form of table (Pt vs Si).
Author Response
We would like to thank the reviewer for their valuable comments that helped us to further improve the quality of the manuscript. Please find in the following the detailed point-by-point response to the reviewers’ comments. Any changes in the revised manuscript according to the reviewers’ suggestions are marked in red.
Reviewer#1
This research study has been well conducted and the results are interesting, but some modification must be addressed before the paper can be accepted for publication.
It would be necessary to introduce the supplementary material in the paper, with some structural modifications, as follows:
- At the end of the Introduction (lines 77-86), refer also to the SEM and AFM results
Authors’ response: We are grateful for this helpful suggestion. We now mention the SEM and AFM analyses in the relevant paragraph of the Introduction.
- Section 2 (Materials and Methods) should be reorganized as follows:
- 2.1. IJD System Upgrade - adding the corresponding paragraph and figures from the Supplementary material
- 2.2. Thin Film Growth
- 2.3. Characterization methods – add the description of SEM and AFM equipments/methods
Authors’ response: We thank the reviewer for the helpful suggestion. In response, we have reorganized the sequence of the figures and incorporated relevant Supplementary Material into the main text, as recommended. The SEM and AFM methods are now described in Section 2.3, Characterization Methods.
- 3 Results and discussion
Add the supplementary material and renumbering the figures.
3.1 Structural and Morphological Characterization (XRD, SEM, TEM, AFM, Raman)
- figure 1 should be split in two by separating the TEM images. If there is selected area electron diffraction (SAED) data to add to the discussion between XRD and TEM
- add from the supplementary material the AFM and SEM results with cross-section SEM images useful for the multilayer vs interface(s) discussion.
Authors’ response: We thank the reviewer for their thoughtful comments. In response, we have incorporated the SEM and AFM analyses previously included in the Supplementary Information into the main manuscript (now presented as the new Figure 2). Additionally, for the sake of completeness, we now include the SEM and AFM analyses of the MoSâ‚‚ multilayer film (Figure 2e,f).
Moreover, we have reorganized the original Figure 1 by separating the XRD and Raman results (now Figure 3) from the corresponding TEM analysis (now Figure 4). The TEM analysis has also been revised to include additional structural information, specifically the FFT pattern.
To better support our interpretation of the self-heating effect resulting from the modified sample holder, we now present complete TEM bright-field cross-sections rather than partial views. This clearly reveals the alternating amorphous-to-crystalline morphology in the as-deposited multilayer and its thickness (~45 nm).
Regarding the interface film, as already noted on page 12 (lines 363–365), “In the interface film, the deposited MoSâ‚‚ thickness is estimated to be less than 5 nm, i.e., the material initially fills the roughness of the substrate as amorphous phase rather than forming distinct layered structures.” For this reason, we believe that including cross-sectional SEM images of the interface film will not support the discussion.
3.2. Chemical Characterization (XPS, UPS)
The central point of the paper is the XPS analysis being a continuation of the study of optimizing the crystalline growth of MoS2 on different substrates using ion beam deposition. A table should be included with the binding energies of the data regarding the Pt and SiO2/Si substrates [references 15, 17]
The UPS results should be also presented in the form of table (Pt vs Si).
Authors’ response: We thank the reviewer for their valuable comment. We have now included in the Supporting Information a table comparing the XPS core-level binding energies with those reported in our previous studies. Regarding the UPS analysis, we note that such measurements have not been performed on the SiOâ‚‚/Si substrates in this work. Furthermore, we believe that a comparison of the current work function and valence band onset data with previous studies is not essential, as it would not provide relevant insights for the optimization of MoSâ‚‚ thin film growth.
Reviewer 2 Report
Comments and Suggestions for AuthorsThe manuscript presents a detailed study on the growth of MoS2 thin films on platinum substrates using ionized jet deposition, with a focus on the structural, chemical, and electronic properties of the films. While the work is well-structured and provides valuable insights, several issues need to be addressed to improve the study. Below are the major concerns and recommendations for revision.
- The introduction section does not fully discuss the advantages and disadvantages of other deposition methods (such as CVD, ALD), and lacks comparison with IJD
- Supplement the limitations of other methods (such as high temperature, high cost) to highlight the advantages of IJD
- In XRD and Raman data, it was not explained why the crystallinity only "slightly increased" after annealing (Figure 1a), while XPS showed a significant reduction in sulfur defects (Figure 2a). The correlation between these two is insufficient
- The reason for the appearance of Fermi edge in UPS data (Figure 4) (sulfur desorption or Pt exposure) has not been verified by other characterizations (such as STM)
- The conclusion mentions the enhancement of MoS2 stability, but does not provide long-term stability testing (such as air aging experiments)
- There are many formatting errors in the references, such as the 2 in MoS2 not being marked with subscripts, and there are many similar errors; The author's format is confusing; The abbreviation of magazine names is confusing; The reference format of the entire manuscript needs to be carefully checked.
Author Response
We would like to thank the reviewer for their valuable comments that helped us to further improve the quality of the manuscript. Please find in the following the detailed point-by-point response to the reviewers’ comments. Any changes in the revised manuscript according to the reviewers’ suggestions are marked in red.
Reviewer#2
The manuscript presents a detailed study on the growth of MoS2 thin films on platinum substrates using ionized jet deposition, with a focus on the structural, chemical, and electronic properties of the films. While the work is well-structured and provides valuable insights, several issues need to be addressed to improve the study. Below are the major concerns and recommendations for revision.
- The introduction section does not fully discuss the advantages and disadvantages of other deposition methods (such as CVD, ALD), and lacks comparison with IJD
- Supplement the limitations of other methods (such as high temperature, high cost) to highlight the advantages of IJD
Authors’ response: We agree with the reviewer’s suggestions and added a paragraph in the introduction to highlight the advantages of IJD with respect to other deposition systems (page 2, lines 52-63)
- In XRD and Raman data, it was not explained why the crystallinity only "slightly increased" after annealing (Figure 1a), while XPS showed a significant reduction in sulfur defects (Figure 2a). The correlation between these two is insufficient
Authors’ response: We thank the reviewer for raising this point. However, in our view, establishing a direct correlation between the XPS S 2p lineshape and crystallinity as observed by XRD is challenging. While the post-deposition annealing process may enable a small fraction of sulfur to recombine within defect-rich Moâ‚“Sáµ§ phases—potentially contributing to a slight improvement in crystallinity and defect reduction—the predominant effect of post-deposition annealing is the loss of amorphous sulfur-containing species, which do not contribute to the development of crystalline order.
- The reason for the appearance of Fermi edge in UPS data (Figure 4) (sulfur desorption or Pt exposure) has not been verified by other characterizations (such as STM)
Authors’ response: We thank the reviewer for this thoughtful consideration. The primary aim of the present study was to optimize crystalline growth at low temperatures by leveraging self-heating through a modified sample holder. A detailed investigation of the desorption of excess sulfur falls beyond the scope of this work. However, future studies are planned—using atom probe tomography—to explore in greater depth the lateral distribution and size of isolated sulfur clusters.
- The conclusion mentions the enhancement of MoS2 stability, but does not provide long-term stability testing (such as air aging experiments)
Authors’ response: We thank the reviewer for raising this point. We have removed the statement referring to “enhancing MoSâ‚‚ stability” from the conclusion, as air-aging experiments are beyond the scope of the present study. However, we would like to note that in our recent publication, we demonstrated that MoSâ‚‚ thin films remain largely stable even after one year of storage in air. [Campedelli et al., Adv. Sustain. Syst., p. 2400979, 2025, doi: 10.1002/adsu.202400979]
- There are many formatting errors in the references, such as the 2 in MoS2 not being marked with subscripts, and there are many similar errors; The author's format is confusing; The abbreviation of magazine names is confusing; The reference format of the entire manuscript needs to be carefully checked.
Authors’ response: We are grateful to the reviewer for the thorough check of the reference list. We have carefully revised the formatting to ensure consistency and have adopted the reference style in accordance with MDPI Surfaces guidelines.
Round 2
Reviewer 2 Report
Comments and Suggestions for AuthorsIt can be accepted in present form