Epitaxial Growth and Optical Properties of Laser Deposited CdS Thin Films

Round 1

Reviewer 1 Report

Paper ID # Coating 1512806 The article has been well-written. I have a few comments to improve the quality of the manuscript. My comments are as follows:

1. The SEM image qualities of Figure 5 (a, b) are look hazy. It is suggested to redo these images.
2. 2. In Figure 4 (b), the authors plot “Film Thickness vs. Microstrain,” which needs more detailed description. The authors showed the error bars, however, the need to include the SD values of all the data points and a proper justification of the higher SD values (as seen from the error bars at different data points).
3. 3. In the same Figure, they also need an explanation for the steep slopes of the lower thicknesses and flat slope for the comparatively higher thicknesses.

Author Response

We thank you for your time spent carefully reviewing the manuscript,  We hope that we have succeeded in responding to your valuable comments and suggestions.
In what follows your comments are in black and the authors’ responses are in red.

• Regarding your comments on the SEM image qualities in Figure 5 (a, b).

The TEM image in Figure 5 (a, b), which were looking hazy, has been reloaded by method more clearly as showing in the manuscript.

• Regarding the comment 2 related to figure (4b), which describing microstrain versus film thickness.

We had been added small paragraph in the explained the variation of microstrain versus the film thickness, and we would like to say this point was explained in detail in the electrical properties study of the CdS thin films in another work (which will be published soon). In which, we found that the variation of microstrain with film thickness having a large effected on the electrical properties of the films.

• Regarding the comment 3 on the same figure (4b), which related to the steep slopes.

We have redrawn the relationship between the microstrain and the thickness of the films. The graph highlights that, the relation between the variation of microstrain with film thickness is exponential relationship as shown in figure in manuscript.

Author Response File: Author Response.docx

Reviewer 2 Report

The manuscript has been sufficiently improved. The information obtained from the result and explanations is well aimed. After thorough reread and grammatical checks, the paper can be accepted in the "coatings" journal.

Author Response

We thank you for your time spent carefully reviewing the manuscript,  also thank you for recommending the possibility of accepting the research in the coating Journal.

Reviewer 3 Report

• The manuscript requires a thorough grammar spell check. I am listing a few examples of improper grammar but the list is not exhaustive –

1. Line 34 – “and have a direct band energy gap at temperature (300 k)” (should be and has a direct band energy gap at room temperature (300 K))
2. Line 42 – “producing a thin-film layers of CdS.” (should be “producing thin films of CdS”)
3. Line 49 – “Some significant advantages for the PLD method” (should be “of the PLD method”)
4. Line 53 – “(VI)” (should be (IV))
5. Line 65 – “The deposition chamber is made of stainless steel, finally pumping system:”
6. Line 81 – “A CdS targets”

• Line 53 – “In 10 or 15 minutes, high-quality samples may be reliably prepared”. This would really depend on the film thickness desired. I would not really call this an advantage.
• In line 56 authors say PLD has become a suitable technique in semiconductor industry. However, in line 59 they say not much work has been done to prepare thin films. So which is it? Authors need to be more clear here.
• While the results reported in the manuscript seem okay, how is the work presented here fundamentally novel when compared to similar studies in the literature that have studied structural properties of CdS films prepared by PLD? Please provide a clear explanation here. (see: https://www.scientific.net/MSF.691.134

https://aip.scitation.org/doi/abs/10.1063/5.0065731

https://journalofscience.org/index.php/GJSFR/article/download/2577/2438/

Author Response

We thank you for your time spent carefully reviewing the manuscript,  We hope that we have succeeded in responding to your valuable comments and suggestions.
In what follows your comments are in black and the authors’ responses are in red.

• Regarding your comments on grammar spell check for the manuscript

We checked the spelling and grammar of all the text with a proofreader.

• Regarding your comment on the time advantage of PLD. “In 10 or 15 minutes, high-quality samples may be reliably prepared”

We would like to say. We reformulated the sentence to become (By controlling the parameters of the pulsed laser, the rate of growth and synthesis of nanoparticles can be controlled as well as restricting the kinetic energy of the evaporated species to control the film growth modes and attributes).

• Regarding your comment on the discrepancy in the wording between the paragraph on line 56 and the paragraph on line 59.

There is no dispute that the PLD technique for preparing thin films from different materials and semiconductors is considered one of the best techniques used.

We paraphrased the paragraphs in line 56 and line 59 of the article and we think they are now clearer.

• Regarding your comment how is the work presented here fundamentally novel when compared to similar studies in the literature that have studied structural properties of CdS films prepared by PLD?

We have added some recent studies on the structural and optical properties of thin films prepared by laser deposition technique in the introduction to the article. In addition to a summary of what was done in this study.

Best regards

Dr: Hamdan Al-shamiri

Round 2

Reviewer 1 Report

I am still not convinced of the authors' corrections in their manuscript. My comments are as follows:

1. For Figure 4 (b), the authors showed the error bars in their previous version. It is not clear why they removed the error bars in their revised version. Instead of removing the bars, it is suggested to include the bars along with the description of the SD values of all the data points in their manuscript.
2. I did not find any explanation regarding the steep slopes of the lower thicknesses (60 – 100 nm) and flat slopes for the comparatively higher thicknesses (100 – 220 nm).

Author Response

We thank you for time spent carefully reviewing our manuscript. We hope to have been successful in responding to your valuable comments.

In what follows your comments are in black and the authors’ responses are in red.

1-Regarding to the comment related to figure (4b), which describing microstrain versus film thickness.

We returned the original figure for the relationship between microstrain with film thickness and we calculated the standard deviation, and the values were put in the table as in the manuscript.

 It is noticeable that the standard deviation increased directly with the increased film thickness and inversely with microstrain. This result fits with the crystal size calculation and the increase of the deposition process.

2- Regarding to the comment related to steep slopes of the lower and higher thickness of film.

We added discussion for this point in the manuscript as the following:

With the increase in the film thickness and the exposure of the material to laser pulses, the number of ions present increases, and therefore the deposition process increases which lead to filling the interstitial voids in the material. The film thickness from 60 nm to 100 nm the intermolecular space is large that is lead to sharp decrease of microstrain and may be the relation become nonlinear relation while after increasing the thickness from 100 nm to 220 nm the intermolecular spaces are decreased, and freedom of ions motion are decreasing that lead to little change of microstrain and the relation between the thin film thickness and microstrain may be linear relation as shown in figure (4b).

                                 Best regards

                                 Dr: Hamdan

Reviewer 3 Report

Authors have addressed most of the concerns from previous round of peer-review. Should be ok to publish.

Author Response

We thank you for time spent carefully reviewing our manuscript. and 

recommendation for published it.

Best regards