Reflectance Minimization of GaAs Solar Cell with Single- and Double-Layer Anti-Reflection Coatings: A Simulation Study

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This study investigates the electrical and optical behaviors of single- and double-layer ARC for gallium arsenide (GaAs) solar cells, using PC1D simulation for single-layer SiO2, and ZnSe, and double-layer SiO2/ZnSe configurations. The results found indicate that the double-layer SiO2/ZnSe ARC structure significantly reduces reflectance and enhances light absorption, leading to higher current density and efficiency.

The topic is interesting; however, the manuscript needs to be revised and the following main points need to be carefully addressed before it can be considered for publication:

1.     The title is too long and should be reduced. First, I suggest removing the words "to improve performance", as this purpose of the work is quite obvious. 

2.     It is necessary to highlight in the text the novelty of the manuscript with respect to the vast literature in the field, as also reported in the manuscript several times (line 46, 76 and so on).

3.     The Introduction needs to be improved. For completeness, among the other methods to reduce the reflection losses in solar cells (lines 43-44), it should be reported also the use of the challenging engineered nanostructures that are promising energy-efficient high-conversion photovoltaic systems, (with the additional advantage of having higher absorption efficiencies) as reported in these relevant papers that deserve mention [https://doi.org/10.1021/acsanm.2c04044; https://doi.org/10.1063/1.3555096]. 

4.     Furthermore, it should be highlighted that the optical properties of ZnSe and ZnSe-based compounds are crucial properties of such ARC layers, as thoroughly studied in this remarkable paper which should be mentioned [https://doi.org/10.1063/1.111592]. 

5.     The PC1D simulation tool used in this work should be clearly and in depth described in the text. 

6.     Regarding the parameters used for the simulations reported in Table 1, the reference of the presented values is reported only for some of them, but not for all (e.g. not for Energy gap, electron affinity, refractive index and so on). This point should be modified by completing all the values with the corresponding reference.

7.     I wonder whether the parameters used for the simulation also considered the change in weather conditions, geographical differences during the solar year (height of sunlight) and so on, and if not, whether this could possibly be done in a future work. 

8.     Fig. 2(c), mentioned at line 125, should be adequately commented inside the text. Also, the meaning of the results reported in Fig. 2 (a), (b) and (c), is not enough clear and should be properly described.  

9.     The quarter-wavelength criterion reported at lines 133-134, should be clearly described in the text. If the quarter-wavelength criterion minimizes the reflectance and maximize the transmittance – as reported in line 134 - the optimized thickness of the ARC layer would seem to be defined by this criterion, and there would be no reason for further investigation on this parameter. The authors should adequately clarify this point inside the manuscript. 

10.  The cumulative photogeneration rate reported at line165 should be better defined. 

11.  The text in lines 201-209 appears confusing and incomprehensible and should be rewritten clearly. Analogously for the text in lines 213-223. 

12.  Fig. 7 shows the diffusion length of GaAs solar cells, how was it calculated? The formula used for this quantity should be reported and commented in the paper. 

13.  The conclusions should clearly show the added value of this work in the field, better identifying the advantages but also the limitations of the presented results and outline possible future developments/perspectives. 

Comments on the Quality of English Language

The article requires careful review by a native English speaker.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Manuscript titled "Reflectance Minimization of GaAs Solar Cell with Single- and Double-Layer Anti-Reflection Coatings to Enhance the Performance: A Simulation Study." presents an important contribution to the field of photovoltaic technology by addressing the efficiency challenges of GaAs solar cells through innovative anti-reflection coating (ARC) designs.

The manuscript is well-structured, and the methodology, the use of PC1D simulations is clearly explained. The findings, including the significant improvement in efficiency using double-layer ARCs, are both compelling and relevant to advancing solar cell performance.

However, prior to my recommendation for publication with MDPI Coatings, I'd like to raise a few issues that has to be addressed:

1.) Figure 1 shows inconsistent resolution across its elements. Please standardize the resolution to ensure clarity and uniformity.

2.) For ARC thickness, the parameter range of 40 nm to 120 nm thickness is well-presented and aligns with the observed optimal spot. However, since real cell parameters can often exceed this range, additional justification for these specific limits would strengthen the study's relevance to practical applications. Please provide further rationale for this choice.

3.) In addition to 2.), table 1, listing the material parameters used in the simulation, appears to compile values from various sources without a clear explanation of their selection. This gives the impression of arbitrary parameter choices. Please provide a justification or reference for the parameter combinations to establish their validity and relevance to the study.

4.)While adding the ARC increases exposure and results in higher Jsc​, which is central to the simulation's success, it can also introduce shunt and series resistance not accounted for in the simulation. Please address how these resistances might impact real-world performance and discuss their omission in the current model.

5.) Figure 3's inset spacing is inconsistent.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript is well written.However some improvements are required for a very good 

quality of  this paper:

1. the originality of this article has to be stressed in comparison with similar published articles.

2. the investigation of this study for other types of solar cells.

3. the improvement of resolution for the Figures 2 and 7 to be more visible.

4. the analysis of industrial implementation of the authors approach to increase the solar cells efficiency.

5. the number of references could be increased until 50. 

Comments on the Quality of English Language

The English could be improved.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have done a really good job, they have addressed all the issues raised and significantly improved the article; however, there are still the following small errors in the references that should be carefully corrected: 

1) Ref [15]: the article number, which is 064314, is missing and should be added to this Ref;

2) Ref [18]: it is incomplete, some details are missing such as publisher, ISBN and so on, and should be completed to easily identify such source;

3) Ref [30]: DOI is missing and should be added;

4) Ref [33]: DOI is missing and should be added. Also, the character "//" appears which is probably a typo.

However, there are several references [such as 33-38, 42-45 and others] without the DOI which should be completed.

Therefore, the authors are requested to carefully check all the references to correct any further errors, thus ensuring the correctness of the data reported in the article.

Once the above mentioned issues are properly addressed, the manuscript will be ready for publication in the journal.

Author Response

# Response to Reviewer 1 Comments

Comments and Suggestions for Authors

The authors have done a really good job, they have addressed all the issues raised and significantly improved the article; however, there are still the following small errors in the references that should be carefully corrected: 

Therefore, the authors are requested to carefully check all the references to correct any further errors, thus ensuring the correctness of the data reported in the article.

Once the above mentioned issues are properly addressed, the manuscript will be ready for publication in the journal.

Author’s Response: We sincerely thank the reviewer for pointing out the small errors in the references of our manuscript. We have addressed these errors and modified the manuscript thoroughly based on the reviewer’s recommendation. The reviewer’s suggestions have helped us significantly to improve the quality of the manuscript. We do hope the reviewer will consider the revised manuscript for publication.

"We sincerely thank the reviewer for their positive feedback and for highlighting the small errors in the references of our manuscript. We would like to mention that we have used the EndNote bibliography software to manage our references. As per the Instructions for Authors, DOI inclusion is not mandatory, and for some references, we could not locate the DOI, which is why it was omitted. Nevertheless, we have carefully reviewed and revised the references to ensure accuracy and completeness. We truly appreciate the reviewer’s suggestions, which have contributed to improving the quality of our manuscript."

Comments 1: Ref [15]: the article number, which is 064314, is missing and should be added to this Ref;

Response 1: Thank you for pointing this out. We have corrected the reference and inserted the article number.

Comments 2: Ref [18]: it is incomplete, some details are missing such as publisher, ISBN and so on, and should be completed to easily identify such source;

Response 2: Thank you for your suggestions. Previous citation Fraunhofer, J.; Schriften, J.v.F.G. Munich. 1888. Changed to “Fraunhofer, J.; Lommel, E.v. Joseph von Fraunhofer's Gesammelte Schriften. Edited by Eugen Lommel. Munich 1888.”

([Google Scholar])

Comments 3: Ref [30]: DOI is missing and should be added;

Response 3: DOI could not be located. However, we have provided Google scholar link to this citation.  [Google Scholar]

Comments 4: Ref [33]: DOI is missing and should be added. Also, the character "//" appears which is probably a typo.

Response 4: The character "//" has been removed.  DOI ( https://doi.org/10.1007/978-81-322-2012-1_59 ) is added and the Google Scholar link is [Google Scholar].

Comments: However, there are several references [such as 33-38, 42-45 and others] without the DOI which should be completed.

Response 5:  34) https://doi.org/10.1109/PVSC.1996.564023

35) https://doi.org/10.3390/cryst12020244

36) https://doi.org/10.1109/ICMDCS.2017.8211589

37) https://doi.org/10.1166/jctn.2013.3124

38) https://doi.org/10.1109/JPHOTOV.2015.2430016

42) https://doi.org/10.1016/j.solener.2022.02.006

43) https://doi.org/10.5755/j01.eee.19.8.5392

44) https://doi.org/10.1109/WCPEC.2006.279575

45) The reference has been changed to Li, Z.; Yang, J.; Dezfuli, P.A.N. Study on the Influence of Light Intensity on the Performance of Solar Cell. Int. J. Photoenergy 2021, 2021, 6648739, doi:https://doi.org/10.1155/2021/6648739.

49) https://doi.org/10.2971/jeos.2013.13010

We sincerely thank the reviewer for insightful and constructive comments on this manuscript. Their feedback has been invaluable in improving the quality, clarity, and depth of our work.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript was improved and could be published now.En

Comments on the Quality of English Language

English could be improved

Author Response

# Response to Reviewer 3 Comments

Comments and Suggestions for Authors:

The manuscript was improved and could be published now.

Comments on the Quality of English Language

English could be improved

Author’s Response: We sincerely thank the reviewer for the insightful review of our manuscript. We sincerely thank the reviewer for their positive feedback and confirmation of our manuscript's readiness for publication. We also appreciate the suggestion regarding the quality of English and have made additional efforts to further refine the language to enhance clarity and readability. Reviewer’s feedback has been invaluable in improving the quality, clarity, and depth of our work.