Investigation of Photoelectron Properties of Polymer Films with Silicon Nanoparticles
Round 1
Reviewer 1 Report
The manuscript compared two types of silicon/P3HT composite as solar cell materials. It is generally interesting to the renewable energy field. Several things that needs to be addressed before it is published.
Why polarons of free P3HT showed two different orientations but this is not shown in P3HT/silicon composite?
What's the energy transfer efficiency in this study, in percentage? Having this number will provide more context for readers.
Author Response
We are thankful to the Reviewer for his comments, which helped us to revise and to improve our manuscript for its better understanding of the readers.
Reviewer 1
Why polarons of free P3HT showed two different orientations but this is not shown in P3HT/silicon composite?
Authors answer
We suppose that addition of Si nanoparticles in P3HT affects the relaxation times of paramagnetic centers. Probably, the relaxation times of the polarons of one of the groups became very short, and the width of the EPR line is very large and the EPR signal became indistinguishable at the background level.
What's the energy transfer efficiency in this study, in percentage? Having this number will provide more context for readers.
Authors answer
Although the efficiency of solar energy conversion of the samples in our study was low (not exceed 5%), we have demonstrated that EPR spectroscopy is effective tool for detection of polarons in nc-Si/P3HT prepared by different techniques. We have added this information in the manuscript (page 7, lines 161-163).
On behalf of the authors,
Sincerely yours,
Prof. Dr. Elizaveta A. Konstantinova
Author Response File: 
Author Response.pdf
Reviewer 2 Report
In fig 2, x.axis what is 1/sm. I think it should be cm! Careless submission.
by the way calling this spectra as typical is not fair while there is broadeneings and S/N is too bad. So it is not typical. (def) and (rot) unclear! what are the not-assigned peaks in spectra? I think the Raman spectra interpretation an presentation is very problematic in this manuscript.
Epr spectra generally shown as solid lines not dotted points.
I dont see any difference compared to dark and illuminated epr spectra in fig 3. Only some improvement in S/N ratio. No other defect centers after light! The same for 4.
How the g factors: g1 g2 and g3 obtained. Here there are many overlapping of epr centers. Without simulation of each center authors cannot be sure 100% that these are 3 different epr center or anisotropy of one center?
"g-tensor were obtained from computer simulation": How, which program and parameters were used? And where is the simulated spectra?
figure: I cant read the scale.
Introdcution is too simple. Authors should extensively discuss the possible defect structures here in terms of EPR.
Manuscript should be revised substantially.
A powerful tool for study the nature and properties of defects is EPR spectroscopy. : please see and cite the following articles for this statement: Physical Review B 86 (1), 014113 (2012); Journal of Alloys and Compounds 605, 34-44 (2014)
Author Response
We are thankful to the Reviewer for his comments, which helped us to revise and to improve our manuscript for its better understanding of the readers.
Reviewer
In fig 2, x.axis what is 1/sm. I think it should be cm! Careless submission.
Authors answer
x-axis (Raman shift) indicate sm-1, for example:
1) Shao, M.; Keum, J.; Chen, J.; He, Y.; Chen, W.; Browning, J. F.; Jakowski, J.; Sumpter, B. G.; Ivanov, I. N.; Ma Y.-Z.; Geohegan, D. B.; Hong, K.; Xiao, K. The Isotopic Effects of Deuteration on Optoelectronic Properties of Conducting Polymers. Nature communications. 2014, 5(1), https://doi.org/10.1038/ncomms4180. ;
2) S. Falke, P. Eravuchira, A. Maternyb, C. Lienaua. Raman spectroscopic identification of fullerene inclusions in polymer/fullerene blends. J. Raman Spectrosc. 2011, 42, 1897–1900.
3) V. Saini, Z. R. Li, S. Bourdo, E. Dervishi, Y. Xu, X. D. Ma, V. P. Kunets, G. J. Salamo, T. Viswanathan, A. R. Biris, D. Saini, A. S. Biris, J. Phys. Chem. C 2009, 113, 8023.
And so on
by the way calling this spectra as typical is not fair while there is broadeneings and S/N is too bad. So it is not typical. (def) and (rot) unclear! what are the not-assigned peaks in spectra? I think the Raman spectra interpretation an presentation is very problematic in this manuscript.
Authors answer
We have made a more detailed description of the data, presented in fig. 2 (page 3, lines 94-104).
Epr spectra generally shown as solid lines not dotted points.
Authors answer
We have made solid lines in Fig3a and 4a.
I dont see any difference compared to dark and illuminated epr spectra in fig 3. Only some improvement in S/N ratio. No other defect centers after light! The same for 4.
Authors answer
We measured the amplitude of the EPR lines before and after illumination. Their ratio is 1.55 in Figure 3 and 1.3 in Figure 4. This means the number of polarons increases under illumination. After light we have not detected other defect centers. For example, in ref.9 (Niesar, S.; Dietmueller, R.; Nesswetter, H.; Wiggers, H; Stutzmann, M. Silicon/ organic semiconductor heterojunction for solar cells. Phys. Stat. Sol. A. 2009, 206, 2775-2781) the authors have not detected other defect centers also.
How the g factors: g1 g2 and g3 obtained. Here there are many overlapping of epr centers. Without simulation of each center authors cannot be sure 100% that these are 3 different epr center or anisotropy of one center? "g-tensor were obtained from computer simulation": How, which program and parameters were used? And where is the simulated spectra?
Authors answer
We agree, therefore we have performed simulation of experimental spectra. The information about the program was in the end of experimental section: “The EPR spectra simulation was carried out using EasySpin MATLAB toolbox”. We have added reference: [17] (page 8, line 218-219). We have added simulated spectra in the manuscript – Fig.3b and Fig.4b. Parameters g1 g2 and g3 is anisotropy of one center.
figure: I cant read the scale.
Authors answer
Excuse me please, what is of number of figure?
Introdcution is too simple. Authors should extensively discuss the possible defect structures here in terms of EPR.
Authors answer
We rewrote the introduction and added new references in the list of references.
A powerful tool for study the nature and properties of defects is EPR spectroscopy. : please see and cite the following articles for this statement: Physical Review B 86 (1), 014113 (2012); Journal of Alloys and Compounds 605, 34-44 (2014)
Authors answer
We have cited (page 2, line 49, 50, 52 and in References- [12] page 8, line 204-206; [13] page 8, line 208-209)
On behalf of the authors,
Sincerely yours,
Prof. Dr. Elizaveta A. Konstantinova
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments to the authors:
Konstantinova et al. are reporting on hybrid solar cells (HSCs) of P3HT with silicon nano-clusters. The nanoparticles are prepared by two different methods. The HSCs are investigated with EPR in addition to some simulation, Raman spectsoscopy, SEM, and J-V measurements. The charge separation and performance of the devices made with Si-nc that was made with two different methods is shown to be different and is discussed.
Major points to be considered:
1- Most of the cited literature is old. Newest reference cited is 2 years old and cited in the last page (ref #17). Similarly, 50% of the cited literature is more than 10 years old. This made the introduction outdated and weakens the presented work as it shows or indicates that it is not related to recent research in the field.
2- The authors should avoid high percentage of self-citation. 45% of the references are from the authors.
3- Literature is not cited ~properly, please avoid making a group of references that you cite in several occasions, such as, [1-6] in page 1 line 24, line 28, line32…
4- A major conclusion seems that Si-nc prepared with electrochemical etching is more effective than laser ablation. It is often noticed that different methods leads to different performances, but the more interesting to know is why. Therefore, any conclusion why it is better? Could a comparison with morphological details, surface chemistry, or other available characterization method give an answer?
5- Please provide more information about the simulation carried out and/or references if possible.
6- How the extraction of g-factor is done, please provide more information for the readers.
Other points:
7- Page 1, line 12, what is the meaning of “separation of nonequilibrium charge…”, it was not mentioned anywhere except here. I expect some related text to be in the discussion, at least explanation of the phrase.
8- The introduction is poorly written, in addition to the points mentioned before here are some examples:
a. Page 1 line 24, “the cost of such batteries…” what batteries? Please try to elaborate and make clearer sentences.
b. Page 1 line, 26, “in addition to low cost of devices” low cost was not discussed before.
c. Page 1 line 28, the PCE of amorphous Si is more than 10%, easiest reference is to check best research solar cells from NRL national lab.
9- Page 2 line 47, Experimental. Please consider citing references for the methods used.
10- Page 5, line 122, what is the transformation of the i-v characteristics? How the measurements were performed and why plot on a semi-log scale? It also seems that the change in current density is very small? Any statistics ?
11- Page 5, line 131, “the possibility of conversion of solar energy in electric one is shown using the structures consisting of P3HT polymer and silicon nanoparticle”. The possibility has been shown in literature many times. The sentence indicates that this is new or for the first time.
12- Figure 6, “A/cm2”...
Author Response
We are thankful to the Reviewer for his comments, which helped us to revise and to improve our manuscript for its better understanding of the readers.
Reviewer
Major points to be considered:
1- Most of the cited literature is old. Newest reference cited is 2 years old and cited in the last page (ref #17). Similarly, 50% of the cited literature is more than 10 years old. This made the introduction outdated and weakens the presented work as it shows or indicates that it is not related to recent research in the field.
2- The authors should avoid high percentage of self-citation. 45% of the references are from the authors.
3- Literature is not cited ~properly, please avoid making a group of references that you cite in several occasions, such as, [1-6] in page 1 line 24, line 28, line32…
Authors answer
We rewrote the introduction, added new references in the list of references and took into account all the comments.
4- A major conclusion seems that Si-nc prepared with electrochemical etching is more effective than laser ablation. It is often noticed that different methods leads to different performances, but the more interesting to know is why. Therefore, any conclusion why it is better? Could a comparison with morphological details, surface chemistry, or other available characterization method give an answer?
Authors answer
The differences in the current-voltage characteristics of our samples are small, so other methods do not give a definite answer, so we excluded this conclusion from the manuscript (see section Conclusion).
5- Please provide more information about the simulation carried out and/or references if possible.
6- How the extraction of g-factor is done, please provide more information for the readers.
Authors answer
The information about the simulation program was in the end of experimental section: “The EPR spectra simulation was carried out using EasySpin MATLAB toolbox”. We have added reference: [17] (page 8, line 218-219). We have added simulated spectra in the manuscript – Fig.3b and Fig.4b. The g-factor values were extracted from program when the best agreement between the experimental and theoretical EPR spectra was achieved. More detailed information in ref. [17].
Other points:
7- Page 1, line 12, what is the meaning of “separation of nonequilibrium charge…”, it was not mentioned anywhere except here. I expect some related text to be in the discussion, at least explanation of the phrase.
Authors answer
We have added some related text in the Abstract.
8- The introduction is poorly written, in addition to the points mentioned before here are some examples:
a. Page 1 line 24, “the cost of such batteries…” what batteries? Please try to elaborate and make clearer sentences.
b. Page 1 line, 26, “in addition to low cost of devices” low cost was not discussed before.
c. Page 1 line 28, the PCE of amorphous Si is more than 10%, easiest reference is to check best research solar cells from NRL national lab.
Authors answer
We rewrote the introduction, added new references in the list of references and took into account all the comments.
9- Page 2 line 47, Experimental. Please consider citing references for the methods used.
Authors answer
We have added references for the used methods in the experimental section and in the list of references.
10- Page 5, line 122, what is the transformation of the i-v characteristics? How the measurements were performed and why plot on a semi-log scale? It also seems that the change in current density is very small? Any statistics ?
Authors answer
We have replaced text (see page 6, lines 152-157). Current-voltage characteristics of the samples were measured using Keithley 6487. We have added this information in the experimental section (page 2, lines 74-75). Semi-log scale is generally accepted (for example, 1) Salikhov, R.B.; Biglova, Y.N.; Yumaguzin, Y.M.; Salikhov, T.R.; Mustafin, A.G. Solar photoconverters based on thin films of organic materials. Tech. Phys. Lett. 2013, 39, 854-859. 2) Niesar, S.; Dietmueller, R.; Nesswetter, H.; Wiggers, H; Stutzmann, M. Silicon/ organic semiconductor heterojunction for solar cells. Phys. Stat. Sol. A. 2009, 206, 2775-2781). The error of the experiment coincides with the size of the experimental points in Figure 6.
11- Page 5, line 131, “the possibility of conversion of solar energy in electric one is shown using the structures consisting of P3HT polymer and silicon nanoparticle”. The possibility has been shown in literature many times. The sentence indicates that this is new or for the first time.
Authors answer
We rewrote the conclusion section and took into account the comments.
12- Figure 6, “A/cm2”...
Authors answer
Y-axis is current density J, A/cm2. Correctly write: current density-voltage, BUT in literature often for short people write: current –voltage characteristics.
See, for example,
1) Salikhov, R.B.; Biglova, Y.N.; Yumaguzin, Y.M.; Salikhov, T.R.; Mustafin, A.G. Solar photoconverters based on thin films of organic materials. Tech. Phys. Lett. 2013, 39, 854-859.
2) Niesar, S.; Dietmueller, R.; Nesswetter, H.; Wiggers, H; Stutzmann, M. Silicon/ organic semiconductor heterojunction for solar cells. Phys. Stat. Sol. A. 2009, 206, 2775-2781.
On behalf of the authors,
Sincerely yours,
Prof. Dr. Elizaveta A. Konstantinova
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
after revisions, this manuscript can be accepted as it is now. good work
Reviewer 3 Report
Thank you for the new version of the article and incorporating the suggested changes.
Round 3
Reviewer 2 Report
The manuscript is ok and can be accepted as it is.
