In₂S₃/C₃N₄ Nanocomposite and Its Photoelectric Properties in the Broadband Light Spectrum Range

Round 1

Reviewer 1 Report (New Reviewer)

Comments and Suggestions for Authors

Dear Editor

I have carefully reviewed the manuscript entitled "In₂S₃/C₃N₄ Nanocomposite and its Photoelectric Properties in the Broadband Light Spectrum Range." The study explores a promising nanocomposite system with broadband photoresponse characteristics, potentially useful for self-powered photodetectors. While the overall topic is timely and fits well within the scope of the journal, there are several important issues that must be addressed before the manuscript can be considered for publication.

1. There is a noticeable shift in writing style and linguistic quality before and after line 55. The earlier sections are more cohesive and academic, whereas the later parts contain grammatical errors, and repetition. A thorough English language editing is strongly recommended to improve clarity and readability.
2. The quality of the figures, especially Figures 4 through 13, is insufficient for publication. Many are low resolution, lack clear labels, and have poor contrast. High-resolution versions with appropriate labeling and figure captions should be provided.
3. The Materials and Methods section lacks critical details. For example, the synthesis protocol for g-C₃N₄ is referred to another publication but should be summarized in this manuscript. Similarly, SEM/TEM sample preparation, instrument parameters, and measurement conditions should be described more clearly to ensure reproducibility.
4. The discussion of heterojunction types and defect-related energy levels is largely based on literature values and lacks direct experimental validation (e.g., UPS, XPS, or PL lifetime analysis). These claims should be presented more cautiously or supported by experimental data.
5. Tables 1–3 are dense and hard to follow. Furthermore, some key photoresponse metrics such as responsivity or detectivity are missing.

Author Response

Dear Sir,

Thank you for your work and checking the repetition rate. We have revised it. The changes have been highlighted in the revision.

 

Sincerely,

Xingfa Ma

Author Response File: Author Response.pdf

Reviewer 2 Report (New Reviewer)

Comments and Suggestions for Authors

The paper can be published after minor revision according to the following suggestions:

Chapter 2.4: It would be useful to provide the instrument descriptions and measurement parameters here, as well. It is complicated to decipher from the reference’s reference. For example, it is not clear how the UV-Vis-NIR photometric measurements were made, in liquid phase with transmission or in solid phase with reflection mode?

Line 166: There is an excess “the”. Delete one of them!

Figure 2: To save place eliminate the lower part of the pictures, as they don’t show any information (not readable), and the scale bar can be put onto the picture.

Figure 3: The figure would be more informative if the peaks mentioned in the text (lines 205-208) were also marked on the diffractogram.

Figure 3-8, 13-16: Quality of the figures are too low, they are blurred. Improve the resolution of the pictures!

Scheme 2: If the height of the lines represent the exact energylevel of CBs and VBs mentioned in the text (lines 411-413), then they are not in correlation.

Line 418: The text is referring to Scheme 3, but there is no any Scheme 3.

Lines 453-454: Why do you think that “It is also possible the oxygen doping from the In2S3/C3N4 nanocomposites.” If it is true, then O-content should be appeared also after removing the effects of Al foil.

Figures on page 19-20-21: They are not referred in the text. Are they supporting informations? In any case put some figure caption to them, in this form they cannot be interpreted.

Author Response

Dear Sir,

Thank you for your work and checking the repetition rate. We have revised it. The changes have been highlighted in the revision.

 

Sincerely,

Xingfa Ma

Author Response File: Author Response.pdf

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

In this manuscript, the authors present the development of the In2S3/C3N4 nanocomposite and investigate its photoelectric properties across a broad spectrum, extending from visible to near-infrared (NIR) light. The authors effectively explore how sulfur sources, electrodes, and bias voltage impact the optoelectronic performance of the nanocomposite. The study demonstrates self-powered photoelectric responses even under zero bias conditions, which could have significant applications in energy harvesting and sensing technologies. The manuscript provides important insights into the defect modulation and interface interactions that contribute to the improved charge extraction and overall performance of the device. The work presented in this manuscript is of interest to the materials science and optoelectronics communities, and the topic is both relevant and timely. The authors have a solid background in this field, and their research offers valuable contributions to the understanding of broadband photoelectric responses in nanocomposites. However, I believe that the manuscript can be improved and clarified with the following revisions:

1. Language Corrections: Some language issues should be addressed to improve the clarity and flow of the text. A thorough proofreading of the manuscript is recommended to fix minor grammatical errors and sentence structure issues.
2. Inclusion of More Recent References: To further strengthen the paper’s background, I recommend citing more recent studies on photoelectric devices that explore different materials or address comparable performance metrics. For instance, papers such as: DOI: 1016/j.mtphys.2023.101034; DOI: 10.1109/JSEN.2019.2920815 ; DOI: 10.1016/j.jnoncrysol.2021.121168

These references would add depth to the literature review and ensure the study is positioned within the context of the latest advancements.

3. Bias and I-V Characteristics: The authors should provide more discussion on the bias voltage and I-V behavior observed in their system. According to the results shown in the manuscript, the photoelectric responses seem to be influenced by bias, and the dark current at 0V might affect the device performance. Highlighting this and discussing the potential implications for device operation and efficiency, especially in terms of Ion/Ioff ratio and charge transport, would help clarify the observed trends.
4. Additional Figures of Merit (FoMs): The manuscript could benefit from a more detailed discussion of other key performance metrics, such as Ion-Ioff, Rise and fall times, self-powered properties and the elaboration complexity of the nanocomposite. I suggest including a new table or comparison chart to provide a side-by-side analysis of the Ion/Ioff ratio and other FoMs from this work against existing literature. This would not only improve the comparison of performance but also highlight the advantages of the proposed In2S3/C3N4 system. Please refer to the suggested references in comment.2

Conclusion:

In conclusion, the In2S3/C3N4 heterostructures presented in this study exhibit promising photoelectric responses across the visible to NIR spectrum. The combination of these materials and their ability to function even without a bias presents a significant advancement in self-powered photoelectric devices. The study’s focus on defect modulation and interface interactions provides valuable insights into material optimization for high-performance devices. However, further clarification on the bias voltage effects, as well as the inclusion of more recent references, is necessary to strengthen the manuscript.

In summary, this work contributes significantly to the development of broadband photoelectric nanocomposites. I would recommend the manuscript for Major Revision before considering it for publication in the journal.

 

Comments on the Quality of English Language

Some language issues should be addressed to improve the clarity and flow of the text. A thorough proofreading of the manuscript is recommended to fix some grammatical errors and sentence structure issues.

Author Response

Dear Sir,

Thank you for your work and comments. We have revised it in the revision according to the comments. The changes have been highlighted in the revision.

Sincerely,

Xingfa Ma

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Comment #1. Manuscript title: In2S3/C3N4 Nanocomposite and its Photoelectric Properties in the Broadband Light Spectrum Range. That means that material is nanocomposite. But in the abstract and in later text, authors claim the presence of heterojunction, Page 2, line 16. "The results indicate that the In2S3/C3N4 heterojunction..." Is there any evidence of the presence of the heterojunction in the samples? TEM or SEM cross-section should show that there is a heterojunction. Although, in Figure 1, the TEM image shows only two unidentified material flakes. There are no indications of In2S3 or C3N4 materials in this picture. And no evidence of In2S3/C3N4 heterojunction. At this point, authors should consider removing the word "heterojunction" (58 hits in the manuscript) from the text. Also, authors must provide evidence of C3N4 presence. Provided XRD results do not indicate the presence of C3N4. Is it C3N4 or C2N3, for example?

Comment #2. Abstract. In2S3 (2.3 eV) is a visible light sensitive class of materials. Authors could consider adding an explanation to this sentence: In2S3 (2.3 eV band gap) is a visible light-sensitive class of materials.

Comment #3. Page 2, line 77. Unclear expression: it is also one of the visible active materials. 

Comment #4. Page 2, line 80. Unclear expression: Although C3N4 based nanomaterials mainly focus on the photocatalytic field... It could be that the majority of researchers focus their studies on the photocatalytic properties of the C3N4-based nanomaterials. 

Comment #5. Page 5, line 150. Only In2S3 diffraction peaks are described in XRD measurements; it is not clear about C3N4, is it amourphous? 

Comment #6. Page 11, line 269. The graphite electrodes with 5B pencil drawings and Au electrodes should be compared using shortened (overlaping) contact conductivity. Simple multimiter-ohmmeter measurements would suffice.

Comment #7. Page 12, line 285. Unclear expression: which increase the chances of more jumps. 

 

 

Comments on the Quality of English Language

Improving the quality of the English language is necessary.

Author Response

Dear Sir,

Thank you for your work and comments. We have revised it in the revision according to the comments. The changes have been highlighted in the revision.

Sincerely,

Xingfa Ma

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The following issues must be addressed:

1. Include reference for the C3N4 band gap value.
2. The last paragraph from Introduction chapter must outline what is new and innovative in this work.
3. Include the purity for each chemical.
4. What kind of water was used during the synthesis?
5. Scheme 2 is not necessary as it can be explained in one sentence.
6. Figure 1 is not clear; the inset valued are not visible as well.
7. Figure 2 – try to work on the figure to look more professional. Remove the 2Theta areas where you don’t have anything (from 0-20, and after 80); include the Miller index in the figure.
8. You don’t need to mention when the light is on/off in the photocurrent graphs.
9. Figure 12 have no relevance for this study.
10. Scheme 3 is too simplified; at least, include the eV values.
11. The correlation between results is not present in this manuscript; try to make these correlations in order to improve the quality of data interpretation.

Author Response

Dear Sir,

Thank you for your work and comments. We have revised it in the revision according to the comments. The changes have been highlighted in the revision.

Sincerely,

Xingfa Ma

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have shown lot of efforts to improve the manuscript and this should be well appreciated. I found the authors have addressed all my comments carefully and in detail by adding more materials in the revised version. Therefore, I suggest accepting this paper.

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript can be accepted in present form.