Solvent Effects on the Structural and Optical Properties of MAPbI3 Perovskite Thin Film for Photovoltaic Active Layer
Round 1
Reviewer 1 Report
Qaid et al. investigated the solvent effects on the structural and optical properties of MAPbI3 perovskite films. This work provides some information about the influence of solvent on quality of perovskite films. It is recommended to be accepted by Coatings after the following issues are addressed.
- The authors calculated the optical bandgaps using the Tauc plots. However, strong scattering signal can be observed from the Abs. spectra, which can affect the results of Tauc plots. The real bandgap of MAPbI3 films should be around 1.5 eV. I think the Tauc plot should be deleted to avoid misleading.
- In Figure 6, the widths for the PL peaks are much narrower than the reported results. According to our experience, this may be the wrong signal, which can be verified by changing the excitation wavelength. I recommend the authors to confirm the PL measurement, or delete the data.
- The authors discussed the effect of annealing and deposition methods on film morphology. I think this related paper should be cited: Angew. Chem. Int. Ed., 2021, 60, 11242. For the effect of solvent on film morphology, I think the authors can explain the difference in film morphology by using the crystal growth theory, see the related paper: J. Semicond., 2021, 42, 072201.
Author Response
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Reviewer 2 Report
Review Coatings
The manuscript entitled “Solvent Effects on the Structural and Optical Properties of MAPbI3 Perovskite Thin Film for Photovoltaic Active Layer”, authors Saif M. H. Qaid, Hamid M. Ghaithan, Bandar Ali Al-Asbahi, and Abdullah S. Aldwayyan, describe the solvent effects in the MAPbI3 thin films. Apart from the novelty of the topic, some things must be improved before going further.
- a) The problem of solvation is quite complicate. The usage of these three solvents has been discussed in many papers. For example, in the following paper: Molecules 2021, 26, 7541.
https://doi.org/10.3390/molecules26247541, all kinds of perovskites were discussed and the solvation is discussed in terms of donor numbers of each solvent. GBL has DN=18 while DMF has 26.6 and DMSO has 29.8. Besides, the donor number of halide ions plays an important role. A higher donor number of solvents together with a higher donor number of halides increases the solubility. The authors should underline what is new in this paper??
- b) Correction of beta. The parameters are correlated with beta.
In the XRD, the instrumental broadening should be accounted, for especially for the large perovskite crystallites. No difference of 0.001 in the halfwidth is significant.
Because the parameters are connected, a much proper conclusion can be obtained from the representation of βcosθ=f(sinƟ). Otherwise, it is a propagation of errors.
- c) Use particle size in SEM instead of crystals. A particle could include several nanocrystalline.
- d) The absorbance is affected by the layer thickness in figure 4. It is better to use figure 5 a) to discuss the efficiency of the photon’s absorption.
Besides it a problem with the determined optical gap. The authors suggest an increase in the bandgap with increase in the solvent polarity. However, from the table 1 and 3:
DMF=3.86 D and 1.25 eV band gap
DMSO=3.96 D and 1.49 eV band gap
GBL=4.27 D and 1.47 eV band gap
As can be seen, it was not a direct connection here.
Author Response
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Reviewer 3 Report
The manuscript entitled "Solvent Effects on the Structural and Optical Properties of MAPbI3 Perovskite Thin Film for Photovoltaic Active Layer", reports a research on MAPBI3 perovskite films which were deposited on glass substrates. In particular, the effect of three specific solvents, such as GBL, DMF, DMSO, on the final characteristics of the products were studied. The prepared samples were extensively characterized. The authors conclude that the results show how the optical qualities of the films can be related to crystallinity based on the different solvents used. The subject matter is consistent with the purpose of the journal. The manuscript is well organized and the reported results are interesting. I have no particular suggestions to send to the authors other than an improvement in the conclusions, which are too vague and generic ,and an improvement in Figure 1 by including the solvent, the latter being the main protagonist of the research.
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
The comments are attached.
Comments for author File: Comments.pdf
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