Evolution of WSe₂ Flakes Synthesized by Thermally Assisted Conversion Method

Round 1

Reviewer 1 Report

Review of “Evolution of WSe₂ Flakes Synthesized by Thermally Assisted Conversion Method" by Vera Marinova et al.

 

The authors have synthesized WSe₂ flakes using a thermally assisted conversion technique. Although the research topic seems interesting, there is a lack of sufficient evidence for the applicability of the produced nanomaterial. I have some comments for improving the quality of this research paper for publication in the coatings journal. You will find in the following my detailed comments:

1. All abbreviations used in the manuscript (chemical compounds, technique, device, etc.) must be defined.
2. Line 116-122: what is the reason for the different densities of the synthesized WSe₂ on the different zone of the substrate?
3. Line 122-124: “the tendency for smooth transition from flake shapes to continuous layer increase with the deposition time of W layer" The authors must explain the reason.
4. Line 140-141: “The profiles of the flakes are measured from 6 nm to 9 nm, indicating that the layer number of the measured flakes is about 8 to 10~12 layers.” From the AFM images, it can be seen that the height profiles are from 6 to 15nm. If it is correct, please modify these lines.
5. Line 166-168: “The peak observed at 375 cm^-1 corresponds to the E_12g + LA(M) combination mode. These peaks do not appear for monolayer WSe₂ but are only visible in few layer WSe₂." Why does the peak at 375 cm^-1 appear for only for few layer WSe₂? Please explain the reason.
6. Line 187-189: “The intensity of photoluminescence emission increases with the increasing the W-layer time deposition (thickness).” Please explain the reason.
7. Line 195-196: “UV-absorption starts below 270 nm, while in the VIS and IR the transmission is 90% up to 2 μm wavelength." Please re-write these lines. It is not understandable.
8. Lines 204-205: “In our case no such emissions are observed confirming the presence of monolayer flakes in all studied samples.” In the AFM section, the number of layers indicated 8 to 12 layers. Why do the authors mention "monolayer flakes in all studied samples"?
9. It seems that the Raman spectra are only about the flakes. The authors claim lines 251-253: "The ability of TAC method to synthesize high quality WSe₂ flakes and continuous films opens a potential route for van de Waals heterostructures for optoelectronic and photonic devices.” If the continuous film is WSe₂, please provide the evidence.
10. The quality of Fig. 6b and c must be improved.
11. There are various publications on synthesizing WSe₂ by the thermally assisted conversion method. Please explain what makes the authors' findings differ from the previous publications.
12. I recommend the authors read this article and use it in the "Introduction":

• https://doi.org/10.3390/coatings8080278

 

 

Best wishes,

Reviewer

 

Comments for author File: Comments.pdf

Author Response

Coatings, Manuscript ID: 1579975

Title: "Evolution of WSe2 flakes synthesized by thermally assisted conversion method" by V. Marinova  et al.

Response to the Reviewers' Comments

First of all, we would like to thank the Reviewer for their very useful and appropriate comments. We take their suggestions and advice into consideration during the revision of our manuscript. Below are the detailed answers and list of changes:

The authors have synthesized WSe₂ flakes using a thermally assisted conversion technique. Although the research topic seems interesting, there is a lack of sufficient evidence for the applicability of the produced nanomaterial. I have some comments for improving the quality of this research paper for publication in the coatings journal. You will find in the following my detailed comments:

1. All abbreviations used in the manuscript (chemical compounds, technique, device, etc.) must be defined.

 

Reply: We thanks for this remark and defined all the abbreviations in the revised version

 

2.Line 116-122: what is the reason for the different densities of the synthesized WSe₂ on the different zone of the substrate?

 

Reply: In principle in TAC method, the density of the deposited by sputtering precursor material is not uniform, and it is lower at the substrate edges and increases towards the center. As a result, the synthesized WSe2 resembles the density pattern of the deposited precursor.

3. Line 122-124: “the tendency for smooth transition from flake shapes to continuous layer increase with the deposition time of W layer" The authors must explain the reason

 

Reply: The WSe2 flakes are created on the places with individual seeds of precursor material, which moving from the edges to the central part of the substrates gradually become island and clusters and finally continuous layer. As the deposition time increase, the spatial density increases, and the transition become smoother.

4. Line 140-141: “The profiles of the flakes are measured from 6 nm to 9 nm, indicating that the layer number of the measured flakes is about 8 to 10~12 layers.” From the AFM images, it can be seen that the height profiles are from 6 to 15nm. If it is correct, please modify these lines.

 

Reply: We highly appreciate this important remark, which is a technical mistake and has been corrected in the revised version “The profiles of the flakes are measured from 6 nm to 15 nm, indicating that the layer number of the measured flakes is about 9 to 20 layers [20]”

5. Line 166-168: “The peak observed at 375 cm^-1 corresponds to the E_12g + LA(M) combination mode. These peaks do not appear for monolayer WSe₂ but are only visible in few layer WSe₂." Why does the peak at 375 cm^-1 appear for only for few layer WSe₂? Please explain the reason.

 

Reply: The sentence "These peaks do not appear for monolayer WSe2 but are only visible in few layer WSe2." has mistakenly appeared during an earlier edition of the text. Such a statement is of course not correct, so this sentence was removed.

6. Line 187-189: “The intensity of photoluminescence emission increases with the increasing the W-layer time deposition (thickness).” Please explain the reason.

 

Reply: In our experiment (using FluoroLog3-22 Spectrofluorometer with 450 W Xe arc lamp light source) the excitation and respectively emission area/spot is larger than the area when laser sources are used (i.e. Raman spectrometers).  The emission signal is integrated on larger area and probably from different depths of the ultrathin layers. Considering the emission intensity, the influence of the substrate should be also of importance. The increasing of PL is probably due to charged defects or inhomogeneities in the charge distribution at the substrate surface. Also the presence of residue of WO₃ affect in general processes of atomic structure of rotation defects on various intra-excitonic energy level transitions and dynamical polarizability. Electron density in the semiconducting monolayer is moreover influenced by, for example, photo doping effect or intrinsic and rotationally created defects. The latter behave as acceptors and lead to a significant p-doping in the WSe₂ [E. Courtade et al., “Charged excitons in monolayer WSe₂: Experiment and theory” Physical Review B 96, 085302 (2017); Y.-C. Lin et al., “Three-fold rotational defects in two-dimensional transition metal dichalcogenides” Nature Communications 6, 6736 (2015); J Jadczak et al., “Upconversion of light into bright intravalley excitons via dark intervalley excitons in hBN encapsulated WSe₂ monolayers, ACS Nano 15 (12) 19165-19174  (2021)]

 

7. Line 195-196: “UV-absorption starts below 270 nm, while in the VIS and IR the transmission is 90% up to 2 μm wavelength." Please re-write these lines. It is not understandable

 

Reply: We apologies for the technical mistake since we preliminary consider presenting transmittance spectra instead of absorbance. This sentence has been revised.

8. Lines 204-205: “In our case no such emissions are observed confirming the presence of monolayer flakes in all studied samples.” In the AFM section, the number of layers indicated 8 to 12 layers. Why do the authors mention "monolayer flakes in all studied samples"?

 

Reply: There are areas with clusters (seeds) with different precursor (W) thickness in all studied samples. In this case the synthesis of monolayers is feasible (achievable). This is explained in the revised version.

9. It seems that the Raman spectra are only about the flakes. The authors claim lines 251-253: "The ability of TAC method to synthesize high quality WSe₂ flakes and continuous films opens a potential route for van de Waals heterostructures for optoelectronic and photonic devices.” If the continuous film is WSe₂, please provide the evidence

 

Reply: Indeed, we had omitted to explicitly specify in the text that Fig. 4b displays Raman spectra of continuous WSe2 layers with different W deposition times. We thank the reviewer for drawing our attention to this. Now we have complemented the text and the caption of Fig. 4 to make it clear that the Raman spectra in Fig. 4b, exhibiting the same WSe2 characteristic features, pertain to continuous films of different W precursor deposition times. 

10. The quality of Fig. 6b and c must be improved.

Reply: The quality of Figs. 6b and c has been improved.

11. There are various publications on synthesizing WSe₂ by the thermally assisted conversion method. Please explain what makes the authors' findings differ from the previous publications.

 

Reply: Indeed, there are several publications using TAC method to synthesis WSe2 layers. However, in our experiments, we use atmospheric pressure TAC, which is not commonly used. Moreover, we study mainly the transitional region from the substrate edges to the center, where the cluster and seeds with different size and shape exists.

12. I recommend the authors read this article and use it in the "Introduction":

https://doi.org/10.3390/coatings8080278

Reply: We thank for this suggestion.

 

Reviewer 2 Report

The subject of presented investigation is interesting and important. The results can interest the big circle of readers. However a set of points in the text should be corrected.
- The quantity of cited literature in the introduction is obviously not enough. If, according to the authors, "continuous films remains a challenging task", it should be supported by another works. As for the sentence about "challenging task", it should be reformulated in traditional English (lines 45-46).
- What is the third zone in fig. 1a? Where is it? What is the reason to heat the empty zone till 680 degrees?
The citation in line 48 should be corrected.
The sentences in lines 110-111 and 130-131 are the same.
In line 167 the cm-1 should be corrected.

Author Response

Coatings, Manuscript ID: 1579975

Title: "Evolution of WSe2 flakes synthesized by thermally assisted conversion method" by V. Marinova  et al.

Response to the Reviewers' Comments

First of all, we would like to thank the Reviewer for their very useful and appropriate comments. We take their suggestions and advice into consideration during the revision of our manuscript. Below are the detailed answers and list of changes:

The subject of presented investigation is interesting and important. The results can interest the big circle of readers. However, a set of points in the text should be corrected.

- The quantity of cited literature in the introduction is obviously not enough. If, according to the authors, "continuous films remains a challenging task", it should be supported by another works. As for the sentence about "challenging task", it should be reformulated in traditional English (lines 45-46).

Reply: We thanks for this remark. The Introduction is rewritten, including appropriate references and explanation concerning the continuous films importance

- What is the third zone in fig. 1a? Where is it? What is the reason to heat the empty zone till 680 degrees?

Reply: We thank the Reviewer for this comment and remarks. The third zone is located at the right side of the tube. It is an empty zone and the temperature is set to ~680°C in order to keep the temperature of the second zone stable. The Figure 1(a) has been modified.

The citation in line 48 should be corrected.

Reply: We apologies for the technical mistake, which has been corrected

 

The sentences in lines 110-111 and 130-131 are the same.

Reply: They are corrected in the revised version

In line 167 the cm-1 should be corrected.

Reply: The unit number has been corrected

 

 

 

Reviewer 3 Report

The manuscript is acceptable with some revision

The materials are very noble, and the method adopted is also suitable. Some modifications are required.

Comments

1. The writing of the manuscript is not clear; in the abstract, it appears that they are characterizing W film. First, discuss the film, then selenization. Also, write clearly, the WSe2 film has been described.
2. Was the deposition pressure 6x10-1 torr.
3. What precaution did you take while using 10% H2.
4. There should be a space between numeral and unit. i.e., 3nm to 3 nm.
5. Improve the contrast of figure 2c (B-D)
6. Figure 3. The legend size can be increased for better clarity.
7. What is the problem with the figure 3D (middle figure).
8. Please mark all the Raman peaks, as this is the only means of structural characterization in the absence of XRD.
9. If possible, you can do the TEM HRTEM to support the structural part.
10. If possible, please give some compositional characterization data.
11. Figure 5 b explain the portion between 200-400 nm
12. Please compare your photo and dark current results with other published work.

Author Response

Coatings, Manuscript ID: 1579975

Title: "Evolution of WSe2 flakes synthesized by thermally assisted conversion method" by V. Marinova  et al.

Response to the Reviewers' Comments

First of all, we would like to thank the Reviewer for their very useful and appropriate comments. We take their suggestions and advice into consideration during the revision of our manuscript. Below are the detailed answers and list of changes:

The manuscript is acceptable with some revision. The materials are very noble, and the method adopted is also suitable. Some modifications are required.

Comments

1. The writing of the manuscript is not clear; in the abstract, it appears that they are characterizing W film First, discuss the film, then selenization. Also, write clearly, the WSe2 film has been described

Reply: We sincerely thank for this important remark. The abstract has been re-written in the revised version.

2.Was the deposition pressure 6x10-1 torr.

Reply: This value is the pressure during the sputtering deposition of W layer precursor. Later on, during TAC process, we work at atmospheric pressure.

3.What precaution did you take while using 10% H₂.

Reply: We used exhaust gases dilution with inert gas.

4.There should be a space between numeral and unit. i.e., 3nm to 3 nm.

Reply: This is corrected in the revised version.

5.Improve the contrast of figure 2c (B-D)

Reply:  We apologize for not good quality of Figs2, which has been improved in a revised manuscript

6.Figure 3. The legend size can be increased for better clarity.

Reply: The legend size of Figs 3 has been increased.

7.What is the problem with the figure 3D (middle figure)

Reply: The figure 3D has been measured again and replaced in the revised version. Here, we would like to point out that the WSe2 sample surface for 5 s of W film pre-deposition is smoother than the other two studied samples (3 s and 8s).

8.Please mark all the Raman peaks, as this is the only means of structural characterization in the absence of XRD.

Reply: The Raman peaks in the panels of Figure 4 were marked as demanded by the Reviewer.

9.If possible, you can do the TEM HRTEM to support the structural part.

Reply: Currently, we have TEM data only for pre-deposited W layers (3s, 5s and 8s), however we need to wait long for available time in TEM instrument for WSe2 samples. Therefore, we apologize we are not able to include complete data in our manuscript.

10.If possible, please give some compositional characterization data.

Reply: We present XPS analysis of WSe₂ for 5s time deposition of W layer on Si/SiO₂ substrate as Supplemented material.

11.Figure 5 b explain the portion between 200-400 nm

Reply: The observed absorbance in the wavelength interval 200-400 nm is supposed to be due to the increased absorbance of fused silica substrate below approximately 230 nm and in the other part of the interval by presence of WO₃ phase in the layers.

12.Please compare your photo and dark current results with other published work.

Reply: The dark and photocurrent values measured in our work are very similar to those reported in Ref. [37,38] cited in the updated Ref list of the manuscript. We sincerely thank the Reviewer to point out this important comparison.

 

 

Reviewer 4 Report

In this paper the authors demonstrated the growth of WSe2 flakes with triangular, dendrite and hexagonal-like shapes by using thermally assisted conversion method. The method has been used in the growth of other TMDs films such as MoS2. The characterization results are detailed and presentation is clear. But some minor defects and ambiguous discussion, which are listed as below, could be improved before acceptance for publication.

1. The format of line 48 should be modified.
2. The scale bars indicated on the optical microscope images shown in figure 2 are unclear for understanding the real size.
3. The titles of the AFM images are unclear for reading.
4. The line colors of W 3s and W 8s on figures 5(a) and (b) are not easy to identify.
5. The authors claim that the samples are p-type based on the I-V characteristics measured in dark and illuminated. But they did not give a detailed explanation about this conclusion. Maybe the authors observed the current decreased when the samples were illuminated and thought of this phenomena imply the samples are p-type? I guess this conclusion could be not correct and need to be checked carefully.
6. The very slow recovery time could be due to many defects in the materials.

Author Response

Coatings, Manuscript ID: 1579975

Title: "Evolution of WSe2 flakes synthesized by thermally assisted conversion method" by V. Marinova  et al.

Response to the Reviewers' Comments

First of all, we would like to thank the Reviewer for their very useful and appropriate comments. We take their suggestions and advice into consideration during the revision of our manuscript. Below are the detailed answers and list of changes:

In this paper the authors demonstrated the growth of WSe2 flakes with triangular, dendrite and hexagonal-like shapes by using thermally assisted conversion method. The method has been used in the growth of other TMDs films such as MoS2. The characterization results are detailed and presentation is clear. But some minor defects and ambiguous discussion, which are listed as below, could be improved before acceptance for publication.

1. The format of line 48 should be modified.

Reply: The format of line 48 has been modified. We apologize for the technical mistake 

2.The scale bars indicated on the optical microscope images shown in figure 2 are unclear for understanding the real size.

Reply: We apologies for unclear images. The scale bars of the optical microscope images have been corrected in the revised version (Figures 2).

3.The titles of the AFM images are unclear for reading.

Reply: corrected in revised version

4.The line colors of W 3s and W 8s on figures 5(a) and (b) are not easy to identify.

Reply: We apologies for the technical mistake, which has been corrected in the revised Figures 5(a,b)

5. The authors claim that the samples are p-type based on the I-V characteristics measured in dark and illuminated. But they did not give a detailed explanation about this conclusion. Maybe the authors observed the current decreased when the samples were illuminated and thought of this phenomena imply the samples are p-type? I guess this conclusion could be not correct and need to be checked carefully.

Reply: We sincerely thanks for this important comment. Indeed, in our preliminary check we only measured the Current-Voltage behavior of studied layers and confirmed the linear behavior. In our experiment and measured values when the current decreased when the samples are illuminated it is not possible to conclude that

6.The very slow recovery time could be due to many defects in the materials.

Reply: Yes, we are agreed with this statement and added it into the text. We assume that the recovery time could be also due to the presence of WO₃ phase.

Reviewer 5 Report

It is an interesting paper about the deposition of WSe2 microcrystals and their characterization. The paper is well organized, but some changes are required prior to publication.

• In the Introduction, no references are reported about the different deposition techniques cited in the text.
• The last part of the Introduction is literally a repetition of the abstract.
• The images of Figure 2 are not adequate. Scanning electron microscopy images should be required.
• To a real characterization of the crystals, XRD spectra could be more useful than Raman ones.
• The quality of Figure 4c is very bad. The spectra should be reported in a clearer way.
• About the Conclusions, there is no evidence in the paper of a “high quality” of the crystals.

Author Response

Coatings, Manuscript ID: 1579975

Title: "Evolution of WSe2 flakes synthesized by thermally assisted conversion method" by V. Marinova  et al.

Response to the Reviewers' Comments

First of all, we would like to thank the Reviewer for their very useful and appropriate comments. We take their suggestions and advice into consideration during the revision of our manuscript. Below are the detailed answers and list of changes:

It is an interesting paper about the deposition of WSe2 microcrystals and their characterization. The paper is well organized, but some changes are required prior to publication.

In the Introduction, no references are reported about the different deposition techniques cited in the text.

Reply: We thank for these important remark. The Introduction part has been rewritten and modified, including addition of new references related to the different deposition/synthesis techniques

The last part of the Introduction is literally a repetition of the abstract.

Reply: The Introduction part has been re-written in the revised version

The images of Figure 2 are not adequate. Scanning electron microscopy images should be required.

Reply: The resolution of Images of Figures 2 has been improved. We sincerely apologize that are not able to perform SEM analysis for the review of our manuscript, however this will be done in our next study of WSe2 layers.

To a real characterization of the crystals, XRD spectra could be more useful than Raman ones.

Reply: XRD analysis is not suitable for such atomic thin layers, therefore we present Raman and XPS analyses.

The quality of Figure 4c is very bad. The spectra should be reported in a clearer way.

Reply: Fig. 4c has been amended to clearer display the deconvolution of the main band in the Raman spectrum W 3s from Fig.4b.

About the Conclusions, there is no evidence in the paper of a “high quality” of the crystals.

Reply: The conclusions are corrected

 

Round 2

Reviewer 1 Report

Review of “Evolution of WSe₂ Flakes Synthesized by Thermally Assisted Conversion Method" by Vera Marinova et al.

 

The authors have appropriately responded to some of my previous concerns. Although the revised article has been modified, some issues still need to be addressed. I have some new comments for improving the quality of this research paper for publication in the coatings journal. You will find in the following my detailed comments:

 

1. In the introduction, the authors name the disadvantages of other TMDC synthesis techniques and Thermally assisted conversion (TAC) advantages. Please write about TAC disadvantages as well and indicate if you overcome the disadvantages in your research.
2. There is no information about the deposition pressure. Please add this information in the experimental details if you used atmospheric pressure deposition.
3. Figure 2c (8 s): the WSe₂ film seems denser in panel C, and the film seems continuous, but in panel D, the substrate can be seen, and the WSe₂ film does not seem continuous. What is the reason?
4. Line 167-168: “They are dominated by three bands (100-150 cm^-1, 220-270 cm^-1 and 34-390 cm^-1) containing the main characteristic WSe₂” Is 34-390 cm^-1 correct? It seems to be 340-395 cm^-1.
5. What is the reason for the different densities of the synthesized WSe₂ on the different zone of the substrate? The authors have already answered this question, but the answer is not accepted. Please explain the fundamental reason behind this phenomenon and add your response to the manuscript.
6. “The intensity of photoluminescence emission increases with the increasing the W-layer time deposition (thickness).” You already answered this question, but the dependence of photoluminescence emission intensity by increasing W thickness is still unclear. Besides, please add the reason in the manuscript.
7. Lines 277-278: “The main part of the substrates excluding the edges consist of continuous WSe₂" From the OM images, it is evident that the large area of the samples (3s and 5s W deposition) is covered with WSe₂ flakes, and only a small area near the centre, the WSe₂ is continuous. So, this claim could be correct only in the case of the 8 s deposited W.
8. Line 282: Please correct “van de Waals” to Van der Waals.

 

Best wishes,

Reviewer

 

Comments for author File: Comments.pdf

Author Response

Review of “Evolution of WSe₂ Flakes Synthesized by Thermally Assisted Conversion Method"

The authors have appropriately responded to some of my previous concerns. Although the revised article has been modified, some issues still need to be addressed. I have some new comments for improving the quality of this research paper for publication in the coatings journal. You will find in the following my detailed comments:

 

1. In the introduction, the authors name the disadvantages of other TMDC synthesis techniques and Thermally assisted conversion (TAC) advantages. Please write about TAC disadvantages as well and indicate if you overcome the disadvantages in your research.

• Concerning the disadvantages: Drawbacks include polycrystalline films and the difficulty of controlling the introduction of dopants. Also the obtaining monolayer is complicated.

These drawbacks are intrinsic and cannot be overcome. The intrinsic disadvantages description is added in the revised manuscript.

2.There is no information about the deposition pressure. Please add this information in the experimental details if you used atmospheric pressure deposition.

• TAC synthesis process is done at atmospheric pressure

3. Figure 2c (8 s): the WSe₂ film seems denser in panel C, and the film seems continuous, but in panel D, the substrate can be seen, and the WSe₂ film does not seem continuous. What is the reason?

• Defects as pin holes are possible to be formed during the W sputtering probably due to stress- if there are no coverage of W – WSe₂ is not formed. Pin-holes free method for deposition as ALD could be used for deposition of precursor W (WO₃) layers.

4. Line 167-168: “They are dominated by three bands (100-150 cm^-1, 220-270 cm^-1 and 34-390 cm^-1) containing the main characteristic WSe₂” Is 34-390 cm^-1 correct? It seems to be 340-395 cm^-1.

The correct sentence is: “They are dominated by three bands (100-150 cm^-1, 220-270 cm^-1 and 360 - 410 cm^-1”. The correction was included in the article text.

5. What is the reason for the different densities of the synthesized WSe₂ on the different zone of the substrate? The authors have already answered this question, but the answer is not accepted. Please explain the fundamental reason behind this phenomenon and add your response to the manuscript.

Sputtering is a line-of-sight deposition technique and deposited layer thickness/density could be different across the substrate surface particularly in ultrathin films near to or under the percolation threshold.  The uniformity depends on the target size, target to substrates distance, substrates rotation.

In sputtered thin films, thickness uniformity is accomplished by using large area targets and appropriate geometry and sputtering conditions. In most applications however the cost of the large targets can become prohibitively high.

This is added into the text: lines 136 to 140.

6. “The intensity of photoluminescence emission increases with the increasing the W-layer time deposition (thickness).” You already answered this question, but the dependence of photoluminescence emission intensity by increasing W thickness is still unclear. Besides, please add the reason in the manuscript.

Owing to the sputtering process characteristics and particular magnetron sputtering system configuration there are regions around the surface edges where the W coverage is not complete and clusters with different lateral size, thickness and spatial/surface distribution exist.

WSe₂ is synthesized by TAC process only at the locations where W clusters exist. With increasing the sputtering time, the number of W clusters increases as well as distribution becomes denser. The photoluminescence signal was integrated from rather larger area than for example those using laser sources, therefore the intensity is enhanced as the number and spatial density of WSe₂ monolayer clusters increase.

7. Lines 277-278: “The main part of the substrates excluding the edges consist of continuous WSe₂" From the OM images, it is evident that the large area of the samples (3s and 5s W deposition) is covered with WSe₂ flakes, and only a small area near the center, the WSe₂ is continuous. So, this claim could be correct only in the case of the 8 s deposited W.

The optical microscope images show only small area of the sample surface. The film formed in samples after 3 and 5s W deposition was not continuous. Then after the selenization the WSe₂ cover continuously the main part of the substrates, however it is possible still some voids to exist in the places where precursor W was not deposited. In the article text the described explanation above is included. New images of the continuous layer part of the samples (3s and 5s W deposition) are added in the manuscript.

8. Line 282: Please correct “van de Waals” to Van der Waals

corrected

Reviewer 3 Report

Without HRTEM how will the microstructure will be visible? Also the language needs to be polished.

If results are similar to others then what is the novelty of this work?

Author Response

Without HRTEM how will the microstructure will be visible? Also the language needs to be polished.

If results are similar to others, then what is the novelty of this work?

Surface microstructure /nanostructure is studied by AFM. Since the obtained WSe₂ is in polycrystalline form there is no need of HRTEM. The results are similar to others however our synthesis of WSe₂ was done at atmospheric pressure instead of more common low-pressure approach. The atmospheric pressure makes the process less expensive.

Reviewer 5 Report

This revised version has been improved and can be accepted for publication.

Author Response

Thank you for your agreement.