Study on the Curing Process of Silver Paste of Heterojunction Solar Cells Using Response Surface Methodology

Round 1

Reviewer 1 Report

Manuscript ID: applsci-859827Type of manuscript: ArticleTitle: Study on curing process of silver paste of heterojunction solar cell using response surface methodologyAuthors: Xin Li, Hongyu Dong, Shaoqing Guo *, Liangfu Zhao *

In this manuscript the statistics response surface methodology (RSM) is applied to explore the relationships between several processing variables and adhesion of a silver contact formed from a silver particle paste. Adhesion was used as figure of merit for silver contacts in heterojunction silicon solar cells. According to RSM the authors use a sequence of designed experiments varying the parameters curing (annealing) time, curing temperature, and the mass fraction of Ag particles and resin to find an optimal adhesion response for low temperature (<200°C) contacts that can be used for heterojunction Si solar cells that consist of i-amorphous Si on p-amorphous Si on, n-Si waver and transparent conducting oxide on both sides on which the Ag paste is screen printed to form the metal contacts after curing.

In addition to find optimal parameters for highest adhesion, the progression of the curing under optimum parameters is analyzed by FTIR from which on the chemical process of curing is sensfully concluded. Further the change of the morphology of the Ag particles before and after curing under optimum process parameters is analyzed with scanning electron micrography, which shows the coalescence of initially separated Ag flakes, from which on high conductivity is concluded.

Although the experiments are made on stainless steel substrates instead of the actual surfaces in the

HJT-Si solar cell and although conductivity of the Ag contacts has not been measured directly and adhesion was used as optimization index instead, the paper can be published after minor corrections, concerning usage of the English and some English expressions:

1. line50 is:  The connections of silver particles each other

change to: The connections of silver particles to each other

2. line 64 is: the interactions among those operation conditions

change to: the interactions among those processing conditions

3. do so inline 75 ….
4. Line 93 is: The organic solvent was prepared as the following steps
5. Change to: The organic solvent was prepared in the following steps
6. Line 94 is: Then heated the mixture to 60
7. Change to: Then the mixture was heated to 60
8. Line 109: the faying surfaces

Change to: the overlapping surfaces

9. Line 112: air oven

Change to: oven under air

10. Line 126: which is one of the RSM for analyze

Change to: which is part of the RSM to analyze

11. Line 175: The F-value of “Model” is 968.62 implies that
12. Change to: The F-value of “Model” is 968.62, which implies that
13. Same in line 180
14. Line 198: explain shortly epoxy value
15. Line 199: K is a key parameter for curing process
16. Change to: K is a key parameter for the curing process
17. Line 206: This is mainly due to that as the curing

Change to: This is mainly due to the fact that as the curing

18. Line 208: reaction is difficult to proceed
19. Change to: reaction is difficult to reach
20. Line 217: the curing time was significantly weaken

Change to: the curing time was significantly weakened

21. Line 249: The FTIR spectrogram at different time interval are shown in
22. Change to: The FTIR spectrogram at different curing times are shown in
23. Same in line 268

Comments for author File: Comments.docx

Author Response

In this manuscript the statistics response surface methodology (RSM) is applied to explore the relationships between several processing variables and adhesion of a silver contact formed from a silver particle paste. Adhesion was used as figure of merit for silver contacts in heterojunction silicon solar cells. According to RSM the authors use a sequence of designed experiments varying the parameters curing (annealing) time, curing temperature, and the mass fraction of Ag particles and resin to find an optimal adhesion response for low temperature (<200°C) contacts that can be used for heterojunction Si solar cells that consist of i-amorphous Si on p-amorphous Si on, n-Si waver and transparent conducting oxide on both sides on which the Ag paste is screen printed to form the metal contacts after curing.

In addition to find optimal parameters for highest adhesion, the progression of the curing under optimum parameters is analyzed by FTIR from which on the chemical process of curing is sensfully concluded. Further the change of the morphology of the Ag particles before and after curing under optimum process parameters is analyzed with scanning electron micrography, which shows the coalescence of initially separated Ag flakes, from which on high conductivity is concluded.

Although the experiments are made on stainless steel substrates instead of the actual surfaces in the

HJT-Si solar cell and although conductivity of the Ag contacts has not been measured directly and adhesion was used as optimization index instead, the paper can be published after minor corrections, concerning usage of the English and some English expressions         

1. line50 is:  The connections of silver particles each other

change to: The connections of silver particles to each other

2. line 64 is: the interactions among those operation conditions

change to: the interactions among those processing conditions

3. do so inline 75 ….
4. Line 93 is: The organic solvent was prepared as the following steps
5. Change to: The organic solvent was prepared in the following steps
6. Line 94 is: Then heated the mixture to 60
7. Change to: Then the mixture was heated to 60
8. Line 109: the faying surfaces

Change to: the overlapping surfaces

9. Line 112: air oven

Change to: oven under air

10. Line 126: which is one of the RSM for analyze

Change to: which is part of the RSM to analyze

11. Line 175: The F-value of “Model” is 968.62 implies that
12. Change to: The F-value of “Model” is 968.62, which implies that
13. Same in line 180
14. Line 198: explain shortly epoxy value
15. Line 199: K is a key parameter for curing process
16. Change to: K is a key parameter for the curing process
17. Line 206: This is mainly due to that as the curing

Change to: This is mainly due to the fact that as the curing

18. Line 208: reaction is difficult to proceed
19. Change to: reaction is difficult to reach
20. Line 217: the curing time was significantly weaken

Change to: the curing time was significantly weakened

21. Line 249: The FTIR spectrogram at different time interval are shown in
22. Change to: The FTIR spectrogram at different curing times are shown in
23. Same in line 268

Respones: Thanks to the reviewer for the suggestions.We are sorry for the mistakes in the usage of English and some English Expressions. We have checked and made corrections of all the mistakes mentioned above in the revision. The term "epoxy value" was also explained in the revision.  Thanks for your suggestion again.

Reviewer 2 Report

In this paper, the authors present the effects of several process variables including curing time (t, min), treatment temperature (T, ℃) and curing agent dosage (m, wt%) on the adhesion strength of HJT silver paste. The reported observations are interesting and may be of value to researchers in this field. However, there are a few shortcomings that need redressal and will improve the manuscript.

Acronyms and abbreviations that are not broadly familiar to readers in all disciplines should be introduced in parentheses following the full term on its first appearance in the text. Abbreviations should be avoided in abstract, but if essential they must be defined at their first mention in the abstract itself.

Define the abbreviations for RSM, SEM, HIT in the abstract.

Author Response

In this paper, the authors present the effects of several process variables including curing time (t, min), treatment temperature (T, ℃) and curing agent dosage (m, wt%) on the adhesion strength of HJT silver paste. The reported observations are interesting and may be of value to researchers in this field. However, there are a few shortcomings that need redressal and will improve the manuscript.

Acronyms and abbreviations that are not broadly familiar to readers in all disciplines should be introduced in parentheses following the full term on its first appearance in the text. Abbreviations should be avoided in abstract, but if essential they must be defined at their first mention in the abstract itself.

Define the abbreviations for RSM, SEM, HIT in the abstract.

Respones: Thanks to the reviewer for this suggestion. RSM, SEM and HJT were all defined in the abstract. Thanks for your suggestion again.