Investigating Influential Parameters for High-Purity Germanium Crystal Growth
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe topic of the work is of interest for publication in Crystals. High purity germanium is an international important research field and there are very few papers about this topic, thereby it would be highly recommended to published it, but there only some remarks.
There is clearly a change in the charge type from p to n-conduction in the crystal, this should be better visualized and not just the net concentration of the charge carriers. The signs are only shown in equation 6.
The authors limit their assumptions to the 4 impurities (B, Ga, Al, P) based on research by Wang et al from 2015. Is there an evidence that there are no other impurities contributing to the balance? Where are the sources of the of contamination - just in the source material?
The mobilities shown in table 1 are not too high for high-purity germanium. Compared to current publications e.g. [https://doi.org/10.1007/s10854-023-11814-8], where values up to µp ~4.67 x104 cm2/Vs are given. The mobilities should be included in the discussion, as this also provides information on compensation.
The measured values as well as the calculated values with several decimal places should be rounded. There is also a lack of information on the error ranges, e.g. in the EPD.
In the conclusion it should be clearly pointed out that the initial concentration was not "determined - were found" but based on calculations and that these could explain the course of the net carrier concentrations.
Comments on the Quality of English LanguageMinor editing of English language required
Author Response
The authors would like to thank the reviewer for valuable comment and suggestions. The response document is attached.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsTitle: Investigating influential parameters for high purity germanium crystal growth
Submitted to: Crystals
Overall Recommendation: Minor Revision
General Comments:
The paper presents a comprehensive investigation into the parameters influencing high purity germanium (HPGe) crystal growth for detector fabrication. The authors have provided detailed information about the materials, methods, results, and discussions related to crystal growth, impurity segregation, and dislocation density measurements. The study is well-structured and contributes valuable insights into optimizing crystal purity and detector efficiency.
Specific Comments:
1. Clarity and Organization:
- The paper is generally well-organized, with a clear structure. However, it would be beneficial to include subheadings within sections to enhance readability and facilitate navigation for the readers.
- Consider breaking down the "3. Result and Discussion" section into subsections for better organization and to highlight specific aspects such as diameter control, crystal characterization, and impurity segregation.
2. Figures and Tables:
- Figures 1, 2, and 3 play a crucial role in understanding the growth process and diameter control. Ensure that these figures are appropriately labeled, and consider providing more detailed captions to guide the reader through the information presented.
3. Equations and Formulas:
- Equations are central to the understanding of the crystal growth process. Consider providing a brief explanation or interpretation for key equations, especially Equation (1) and Equation (2).
4. Impurity Segregation:
- The section on impurity segregation provides insightful information, but a more detailed discussion on the implications of impurity concentrations, especially B, Al, Ga, and P, on detector performance could enhance the paper's impact.
5. Language and Terminology:
- The language used is generally clear and concise. However, some sentences could be rephrased for improved clarity. For example, in the "3. 3. Result and Discussion" section, a sentence starts with "The primary factor...," which could be revised for better readability.
6. Conclusion:
- The conclusion section is concise but could be expanded to include a summary of the key findings and their implications for future research or applications.
Minor Revisions Suggested:
- Enhance figure captions for better clarity.
- Consider reorganizing the "3. Result and Discussion" section with subheadings.
- Provide explanations or interpretations for key equations.
- Ensure consistency in referencing and citation style.
- Consider expanding the conclusion to summarize key findings.
Overall, the paper presents valuable contributions to the field, and with the suggested minor revisions, it will further improve the clarity and impact of the study.
Comments on the Quality of English Languagenone
Author Response
The authors would like to thank the reviewer for valuable comment and suggestions. The response document is attached.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThis article examines the factors influencing the production of bulk germanium crystals with high structural perfection for high energy physics application.
The work can be published, but there are a number of minor comments.
In the Introduction, it is necessary to indicate the current state of the growth of germanium crystals and its quality (weight and dimensions, purity, etc.) in order to use these data as a reference for comparison.
Figure 4. Based on what considerations the positions of the slices S were chosen, it is necessary to provide explanations in the text.
Section 3.3. The position of the solidification fraction g needs to be connected by linear dimensions in figures 2 or 4, I think this is not difficult. Figures 2 and 4 can be combined; this will not affect the quality of the manuscript and will allow you to show the data more compactly and succinctly.
It is completely unclear what initial charge was used for crystal growth (lines 89-90). Be specific about this question! Indicate the level of impurities in the original charge. What is the oxygen level in the grown crystals?
It is necessary to justify in detail the choice of minor impurities for analysis. Why were only the four indicated (B, Al, Ga, P) selected? What is known about the level of other impurities, it is probably necessary to provide data from a study of the complete impurity composition using mass spectrometry.
Section Conclusion: What conclusions can be drawn? How will the data obtained improve the quality of germanium crystals and what needs to be done to achieve this?
Author Response
The authors would like to thank the reviewer for valuable comment and suggestions. The response document is attached.
Author Response File: Author Response.pdf
