Lead ethyl dithiocarbamates: efficient single-source precursors to PbS nanocubes

Lead ethyl dithiocarbamates have been successfully used as single-source precursors for the deposition of PbS using spin coating followed by annealing at moderate temperatures. The thin films were characterized using a powder X-ray diffractometer and were found to be face-centred cubic with the (200) plane being the most preferred orientation. Scanning electron microscopy images showed the formation of well-defined cubes. Optical band gaps of PbS thin films were estimated using Tauc plots as 0.72, 0.73 and 0.77 eV at annealing temperatures of 250, 300 and 400°C. These band gaps were all blue shifted from the bulk value of 0.41 eV. Energy-dispersive X-ray analysis was used to determine the composition of the thin films which showed an approximately 1 : 1 Pb to S ratio.


Recommendation? Accept with minor revision (please list in comments)
Comments to the Author(s) In this manuscript, you presented that lead ethyl dithiocarbamates have been successfully used as single source precursors for the deposition of PbS using spin coating followed by annealing at moderate temperatures. Although the method is unique, there are still some shortcomings in the paper. I believe the paper may be accepted for publication after carefully addressing the following points.
1-In your paper, you stated that you have synthesised the Single source precursors, maybe you can characterize it, not by just words.
2-On line 16 of paper 6, in the sentence"The 100% conversion of the complex to PbS results in 44.60 % of the total mass.","44.6%" did not appear in the corresponding references. Can you explain more clearly?
3-For the SEM images, the stuctures changing mechanism of PbS nanocrystal with temperature increase is unclear.
4-In tabel 1, the form should be a three-line table.
6-The analysis of XRD data in this paper need to be improved. There are many previous works about the analysis of XRD data, such as "10.1016/j.electacta.2018.10.039" ,"10.1016/j.snb.2019.02.026"and so on, and the authors could refer them to enrich your argument and increase the persuasiveness of your article.

Review form: Reviewer 2
Is the manuscript scientifically sound in its present form? No

Do you have any ethical concerns with this paper? No
Have you any concerns about statistical analyses in this paper? No

Recommendation?
Major revision is needed (please make suggestions in comments)

Comments to the Author(s)
The work is interesting and they prepared cubic shape PbS particles from the single precursor Lead ethyl dithiocarbmate. Since the work only the synthesis process of PdS particles. So, to improve the quality further of the work, need more characteristic information of the prepared PdS materials. If author replied with the answer to all question, then the paper can be published after careful observation. 1. It is necessary to highlight that the Lead ethyl dithiocarbmate is not yet used by another author to prepare PdS particles by using the same procedure. For this case, the author needs to search for literature and write the asked information. 2. It is requested to provide PL or UV-visible of PdS particles. Based on the PL or UV-visible, the author needs to give some positive discussion point in their articles to highlight the prepared PdS materials for different application. 3. TEM image of PdS is also required. The editor assigned to your manuscript has now received comments from reviewers. We would like you to revise your paper in accordance with the referee and Subject Editor suggestions which can be found below (not including confidential reports to the Editor). Please note this decision does not guarantee eventual acceptance.
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1-In your paper, you stated that you have synthesised the Single source precursors, maybe you can characterize it, not by just words.
2-On line 16 of paper 6, in the sentence"The 100% conversion of the complex to PbS results in 44.60 % of the total mass.","44.6%" did not appear in the corresponding references. Can you explain more clearly?
3-For the SEM images, the stuctures changing mechanism of PbS nanocrystal with temperature increase is unclear.
4-In tabel 1, the form should be a three-line table.
6-The analysis of XRD data in this paper need to be improved. There are many previous works about the analysis of XRD data, such as "10.1016/j.electacta.2018.10.039" ,"10.1016/j.snb.2019.02.026"and so on, and the authors could refer them to enrich your argument and increase the persuasiveness of your article.

Reviewer: 2
Comments to the Author(s) The work is interesting and they prepared cubic shape PbS particles from the single precursor Lead ethyl dithiocarbmate. Since the work only the synthesis process of PdS particles. So, to improve the quality further of the work, need more characteristic information of the prepared PdS materials. If author replied with the answer to all question, then the paper can be published after careful observation. 1. It is necessary to highlight that the Lead ethyl dithiocarbmate is not yet used by another author to prepare PdS particles by using the same procedure. For this case, the author needs to search for literature and write the asked information. 2. It is requested to provide PL or UV-visible of PdS particles. Based on the PL or UV-visible, the author needs to give some positive discussion point in their articles to highlight the prepared PdS materials for different application. 3. TEM image of PdS is also required.

RSOS-190943.R1 (Revision)
Review form: Reviewer 2 Is the manuscript scientifically sound in its present form? Yes

Recommendation?
Accept as is

Comments to the Author(s)
The author replied and provided all of the necessary question and data. So, the paper can be published. Comments to the Author(s) The author replied and provided all of the necessary question and data. So, the paper can be published.

Response to reviewers
Reviewer 1 Sn Comment Response 1.
In your paper, you stated that you have synthesised the Single source precursors, maybe you can characterize it, not by just words.
Although the single crystal has been reported earlier, the complex was characterized by using micro-elemental analyses, infrared spectroscopy, melting point, and 1 H NMR which were all indicated in the write-up.

2.
On line 16 of paper 6, in the sentence"The 100% conversion of the complex to PbS results in 44.60 % of the total mass.","44.6%" did not appear in the corresponding references. Can you explain more clearly?
The reference is on the "The difference however between the two values is 4.90% which implies that the compound can be decomposed to produce PbS as residue." The corresponding reference also reported that the % residue of a complex when converted to the metal chalcogen is lower than the % residue obtained from the TGA analyses.

3.
For the SEM images, the structures changing mechanism of PbS nanocrystal with temperature increase is unclear.
As the temperature increases (400 °C), the crystals have high surface energy and therefore they collide faster leading to the formation of conjoined crystals as seen in Figure 3e. This observation is however not prominent at lower temperatures (250 °C) 4.
In table 1, the form should be a three-line table.
The correction has been done.

6
The analysis of XRD data in this paper need to be improved. There are many previous works about the analysis of XRD data, such as "10.1016/j.electacta.2018.10.039" ,"10.1016/j.snb.2019.02.026"and so on, and the authors could refer them to enrich your argument and increase the persuasiveness of your article.
The references have been looked at and cited appropriately to enrich the arguments.