Hybrid Gold-Based Perovskite Derivatives: Synthesis, Properties, and Prospects in Photovoltaics
and Peng Gao 1,2,3,4,*Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe paper reports on growth and characterization of 6 new hybrid perovskite derivatives based on gold, which have been grown by a cost-effective hydrothermal method. The first-principles calculations revealed that 4 of the synthesized materials are suitable for the development of solar cells, since their spectroscopic limited maximum efficiency (SLME) is around 30% in films with thickness of 0.5 μm. The paper is expected to be of interest for designers of solar cells. The paper is of good scientific quality. However, the following issues should be addressed:
1. The calculated band structure and bandgap of the grown materials is compared with the experimental value deduced from spectral dependence of the absorbance. It would be useful also to compare the calculated spectral dependence of the absorption coefficient with the measured real value for the synthesized materials.
2. The calculated value of SLME values of around 30% is compared with the theoretical maximum efficiency of Si material (27%). It would be useful to compare this value with the SLME values of methylammonium-formamidinium based perovskite cells, for which an experimental value of power conversion efficiency over 20% has been measured, according to the recent review: Lu et al, Inorganics 2024, 12, 128. https://doi.org/10.3390/inorganics12050128, as well as with other halide perovskite solar cells, for which an experimental value around (25-26)% has been reported, according to the recent review: Machín et al, Materials 2024, 17, 1165. https://doi.org/10.3390/ma17051165.
3. In the last line of page 2, it should be Walusiak et al. instead of Benjamin et al.
Author Response
RESPONSE TO REVIEWERS
Reviewers’ comments are in black
Our responses are in blue.
The additional or revised sentences cited from the revised manuscript or Supplementary information are highlighted in yellow.
Reviewer #1: The paper reports on growth and characterization of 6 new hybrid perovskite derivatives based on gold, which have been grown by a cost-effective hydrothermal method. The first-principles calculations revealed that 4 of the synthesized materials are suitable for the development of solar cells, since their spectroscopic limited maximum efficiency (SLME) is around 30% in films with thickness of 0.5 μm. The paper is expected to be of interest for designers of solar cells. The paper is of good scientific quality. However, the following issues should be addressed:
- The calculated band structure and bandgap of the grown materials is compared with the experimental value deduced from spectral dependence of the absorbance. It would be useful also to compare the calculated spectral dependence of the absorption coefficient with the measured real value for the synthesized materials.
Response: To better ascertain the potential of all materials in the field of solar cells, measuring the optical absorption coefficients of thin film samples is crucial. However, due to the poor solubility of hybrid organic-inorganic perovskites and their derivatives, we encountered difficulties in the thin film fabrication process and have not yet obtained dense films. Therefore, we are currently unable to measure the experimental optical absorption coefficients of thin film samples. We are actively exploring new thin film preparation processes and methods to improve future testing related to thin films and manufacture solar cell devices.
On page 3: ‘In our attempts to prepare thin films by redissolving those hybrid gold-based perovskite derivatives and via spin coating, we encountered solubility issues in most polar solvents and poor film formation, which is one of the challenges faced by many gold-iodide compounds. We are currently exploring the relevant film preparation technology to prepare solar cell devices in the lab.’
- The calculated value of SLME values of around 30% is compared with the theoretical maximum efficiency of Si material (27%). It would be useful to compare this value with the SLME values of methylammonium-formamidinium based perovskite cells, for which an experimental value of power conversion efficiency over 20% has been measured, according to the recent review: Lu et al,Inorganics 2024, 12,128. https://doi.org/10.3390/inorganics12050128, as well as with other halide perovskite solar cells, for which an experimental value around (25-26)% has been reported, according to the recent review: Machín et al, Materials 2024,17, 1165. https://doi.org/10.3390/ma17051165.
Response: We have replaced the reference material of SLME with a more meaningful organic-inorganic hybrid perovskite and have newly referenced several reports. See page 12, line 1
Recently, experimental values for methylammonium-formamidinium-based perovskite cells have exceeded 20%, with the highest recorded value reaching 26.00%, approaching its theoretical maximum limit efficiency. [28,29 https://doi.org/10.3390/inorganics12050128ï¼›https://doi.org/10.3390/ma17051165.]
- In the last line of page 2, it should be Walusiak et al. instead of Benjamin et al.
Response: Thank you for pointing out the mistakes. The corrections have been made.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsTitle: Hybrid Gold-Based Perovskite Derivatives: Synthesis, Properties, and Prospects in Photovoltaics
Journal: Inorganics
Manuscript number: inorganics-3026025
The paper is devoted to studying six new hybrid gold-based perovskite derivatives, such as [(C6H8N2)(AuI4)(AuI2)](3AMPY), [(C6H14N2)(AuI4)(AuI2)](3AMP), [(C8H12N)(AuI4)](2PEAI), [(C4H14N2O)(AuI4)2](OBA), [(C6H18N2O2)3(AuI4)4(I3)2](DDA), [(C10H26N2O3)(AuI4)(I3)](TOTA), obtained through hydrothermal method. The conditions of synthesis, properties, and prospects in photovoltaics of organic-inorganic gold-based perovskite derivatives are considered.
The results obtained are of scientific interest and can be used for applications in the field of solar cells.
The subject matter is suitable for the journal of Inorganics.
However, there are several points that require further clarification by the authors.
General remark:
Graphical abstract.
The schematic structure of a planar perovskite solar cell is indicated incorrectly. The main element of such a cell is a perovskite semiconductor layer, which generates charge carriers (electrons and holes) under the influence of incident solar radiation. Therefore, it is a perovskite layer that shall be shown, instead of a light absorbing layer.
In my opinion, the experiments and research results presented in the manuscript by the authors for hybrid gold-based perovskite derivatives are incomplete. The synthesized compounds contain gold and therefore Raman spectroscopy must be used to analyze their structure (see, for example:
H. Murasugi, S. Kumagai, H. Iguchi, M. Yamashita, S. Takaishi, Organic–Inorganic Hybrid Gold Halide Perovskites: Structural Diversity through Cation Size, Chem. Eur. J. 2019, 25, 9885;
Kojima, Norimichi, Gold Valence Transition and Phase Diagram in the Mixed-Valence Complexes, M2[AuIX2][AuIIIX4] (M = Rb, Cs; X = Cl, Br, and I), Bulletin of the Chemical Society of Japan, 2000, 73, 1445-1460).
The use of Raman spectroscopy will allow demonstrating photo-induced gold valence transitions for the different organic-inorganic gold-based perovskite derivatives. Light absorption by gold complexes is a secondary process for perovskite films.
Considering the above mentioned, I think the paper in its present form needs a major revision.
Author Response
RESPONSE TO REVIEWERS
Reviewers’ comments are in black
Our responses are in blue.
The additional or revised sentences cited from the revised manuscript or Supplementary information are highlighted in yellow.
Reviewer #2: The paper is devoted to studying six new hybrid gold-based perovskite derivatives, such as [(C6H8N2)(AuI4)(AuI2)](3AMPY), [(C6H14N2)(AuI4)(AuI2)](3AMP), [(C8H12N)(AuI4)](2PEAI), [(C4H14N2O)(AuI4)2](OBA), [(C6H18N2O2)3(AuI4)4(I3)2](DDA), [(C10H26N2O3)(AuI4)(I3)](TOTA), obtained through hydrothermal method. The conditions of synthesis, properties, and prospects in photovoltaics of organic-inorganic gold-based perovskite derivatives are considered.
The results obtained are of scientific interest and can be used for applications in the field of solar cells. The subject matter is suitable for the journal of Inorganics. However, there are several points that require further clarification by the authors.
General remark:
Graphical abstract.
1.The schematic structure of a planar perovskite solar cell is indicated incorrectly. The main element of such a cell is a perovskite semiconductor layer, which generates charge carriers (electrons and holes) under the influence of incident solar radiation. Therefore, it is a perovskite layer that shall be shown, instead of a light absorbing layer.
Response: Thank you for pointing out the mistakes. We have corrected the errors and updated the TOC image.
2.In my opinion, the experiments and research results presented in the manuscript by the authors for hybrid gold-based perovskite derivatives are incomplete. The synthesized compounds contain gold and therefore Raman spectroscopy must be used to analyze their structure (see, for example:H. Murasugi, S. Kumagai, H. Iguchi, M. Yamashita, S. Takaishi, Organic–Inorganic Hybrid Gold Halide Perovskites: Structural Diversity through Cation Size, Chem. Eur. J. 2019, 25, 9885;
Kojima, Norimichi, Gold Valence Transition and Phase Diagram in the Mixed-Valence Complexes, M2[AuIX2][AuIIIX4] (M = Rb, Cs; X = Cl, Br, and I), Bulletin of the Chemical Society of Japan, 2000, 73, 1445-1460).The use of Raman spectroscopy will allow demonstrating photo-induced gold valence transitions for the different organic-inorganic gold-based perovskite derivatives. Light absorption by gold complexes is a secondary process for perovskite films.
Response: Thanks for your comments. Raman spectroscopy is one of the most powerful methods to investigate gold valence transitions for the different organic-inorganic gold-based perovskite derivatives. The Raman spectra of these gold-based perovskite derivatives were obtained successfully through testing and corresponded to the valence states of the gold elements in these compounds.
On Page 7, line 26 and Figure 5.
‘Raman spectroscopy is one of the most effective methods for studying the gold valence transitions of various organic-inorganic perovskite derivatives. To further demonstrate the accuracy of the valence state of Au elements in our crystal structure, we obtained the Raman spectra of these compounds through testing, as shown in Figure 5. Analyzing the Raman spectra, we found peaks corresponding to Au-I bonds near 130 cm-1 for all compounds, consistent with the literature reports.[24] Further analysis, as shown in Figure 2 (a, b), reveals that 3AMP and 3AMPY contain [AuIIII4]- and [AuII2]- units, where the Au-I bond length in the [AuIIII4]- units is longer than that in the [AuII2]- units (see Figure S2). By comparing the longer Au-I bond in the [AuIIII4]- units (around 2.62 Å) with that in the [AuII2]- units (around 2.55 Å), we attribute the lower-lying modes, A1 (127.9 cm-1) and A2 (131.2 cm-1) to the [AuIIII4]- units. Moreover, the higher modes, B1 (131.2 cm-1) and B2 (133.8 cm-1) are indicative of [AuII2]- units.[25] Additionally, in 2PEAI, OBA, DDA, and TOTA, the Au ions and I ions form single [AuIIII4]- units (Figure 2 (c-f)), corresponding to individual Au-I modes (A3, A4, A5, and A6). The results of Raman spectroscopy testing correspond well with our crystal structure, demonstrating the accuracy of the valence state of Au elements in the crystal structure.’
Figure 5. Raman spectra for hybrid gold-based perovskite derivatives at 300K.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsThe issues raised have been properly addressed
Reviewer 2 Report
Comments and Suggestions for AuthorsThe authors took into account all the reviewers’ comments and the revised manuscript can be accepted for publication.
