Light Output, Thermal Properties, and Reliability of Using Glass Phosphors in WLED Packages

Round 1

Reviewer 1 Report

This manuscript “Light output, thermal characteristics, and reliability of using glass phosphors in WLED packages”  is a research manuscript that compare PiS and PiG for WLED packages

The experimental work is well described and well written, there are some problems with the figures, and the explanations in the abstract and introduction phase. The work is interesting and offer well quantify information of the new methods of coating WLEDs. The manuscript is written from expertise to expertise in this area, for that I contemplate the possibility that other reviewer show weakness in the redaction or low level of explanations but is a good work.

The comments to the manuscript are these:

1. Is excessive long and excessive detailed. The abstract is not a summary of the manuscript. The recommendation by the Coating Word template are 200 works maximum. The first phrase of the abstract is usually for indicate the relevance of the work in this case study the advantage of replace the PiS the common process by WLED by PiG. Furthermore, you will be reduce your abstract to 200 works. Probably some of the information will be loss, but is not a problem. The authors will be maintaining the relevant information.  From https://www.mdpi.com/journal/coatings/instructions “Abstract: The abstract should be a total of about 200 words maximum. The abstract should be a single paragraph and should follow the style of structured abstracts, but without headings: 1) Background: Place the question addressed in a broad context and highlight the purpose of the study; 2) Methods: Describe briefly the main methods or treatments applied. Include any relevant preregistration numbers, and species and strains of any animals used. 3) Results: Summarize the article's main findings; and 4) Conclusion: Indicate the main conclusions or interpretations. The abstract should be an objective representation of the article: it must not contain results which are not presented and substantiated in the main text and should not exaggerate the main conclusions.”
2. The authors will be including all the acronyms in the text, and do not consider the abstract how part of this text. For example, PiS and PiG acronyms have in the abstracts and not in the introduction. Review all the acronyms.
3. Order of Sub-figures. In Figure 1 PiG is to the Left and PiS to right (b). That is the contrary position of the rest of graphics and figures, as (Figure 4). Maintain the coherence in the order of explanations in text and Sub-figures (a), (b), I think the more easy way is change only Figure 1. But review all sub-figures order.
4. Size of axes text in Figures. The axes test size of Figure 3 can be a good example for other Figures, because Figures 5, 6, 7, has small text in the axes and titles.
5. The references are well use but are scarce, is it need more references (i.e 6 or more), specially of the last years, for demonstrate: some generalized affirmations, the relevance of the work and the comparison with other works. Example of generalized affirmation that need additional references are “Yttrium aluminum garnet (YAG) phosphor in WLEDs exhibits problems associated with thermal quenching owing to the high operating current of LEDs. With decreased LED efficiency as a function of higher operating current, the temperature of the LEDs in-creases and this efficiency is lost as heat.”. Example of comparison with other works are use in 3. Results and Conclusions for compare your results with other works. You can use recent references in open publication journals if do not have access to editorial pay articles. But personally, I think that use 20 or more references increase the professional aspect of the paper, obviously this is a decision of the authors.
6. Figure 9, it is need explain if the samples are of PiG of PiS WLED.
7. Section 2.1. If it is possible include proximally the size of the LED chip, the nominal power at 350 mA, and the density current, and any other information that you can include over the experiment. Obviously the density current or power can be obtained from other results but these additional information can offer to the reader an easy and good reference of the LED operation conditions.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

The authors presented their paper entitled "Light output, thermal characteristics, and reliability of using glass phosphors in WLED packages". In this work, the authors investigate the light output and thermal characteristics in two packing structures WLED through reliability tests. After reviewing the manuscript, the reviewer recommends some minor revisions to make the manuscript suitable for publication in Coatings. I attach a document in which I include comments on the manuscript.

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

The authors in the manuscript "Light output, thermal characteristics, and reliability of using glass phosphors in WLED packages" presented the results quite interestingly. But the experimental section could be improved to give a clear picture of the work done to the reader. 

Here are some of the suggestion which should be implemented before the manuscript could be published in the journal. 

1. There are thousands of glass materials available. What is the glass material used by the authors to produce PiG . How compatable is the glass material with the YAG phosphor to make PiG. A clear explanation is missing in the manuscript.
2. The same explanation for the proceduction of PiS must by given.
3. It seems there are no considerable changes when PiS is replaced with PiG. What elese could improve the durability for high temperature applications. 
4. Do a different glass material would fetch for improvement in the results?
5. The authors if provided original pictures of PiS, PiG and the total LEDs with PiG and PiS makes the manuscript more appealing. 

Author Response

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Author Response File: Author Response.pdf

Reviewer 4 Report

Have gone through this manuscript entitled "Light output,thermal characteristics,and reliability of using glass phosphors in WLED packages" and could find interest. Author presented comparative data on PiG and PiS WLED devices. Even though the paper shows some important results but the paper is poorly written and I do not recommend this for publication at this current stage,
Here are couple of suggestion to improve the manuscript
- Reduce the abstract and write what was investigated and what found(in short form)
- Introduction is too short and need more references. Problem statement should be clear
- Results need analysis - not what observed
- To present comparative data - statistical analysis needed.

Author Response

Please see attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

In the revised manuscript "Light output, thermal properties, and reliability of using glass phosphors in WLED packages", the authors had made all the changes suggested by the reviewer. Hence, in the present format it can be published in the journal. 

Reviewer 4 Report

Agree. Accept as it is now.