Thermal and Optical Analysis of Quantum-Dot-Converted White LEDs in Harsh Environments
Round 1
Reviewer 1 Report
Suggestions are taken in the Comments.
Comments for author File: 
Comments.pdf
Author Response
In Table 1:
- What causes that before aging the electro-optical conversion efficiency (EOCE) of the module N2 (Silicone) is about 14% larger than that of the basic N1 (chip)? What physical or chemical effects provoke this EOCE enhancement?
Response: This is mainly because that the silicone encapsulation in module N2 reduces the interfacial refractive index difference between the LED chip and the air, and thus more light can be extracted from the chip.
- What causes that before aging EOCE factor of the module N3(Phosphor-silicone) decreases about 13% than that of the module N2 (Silicone)? May be authors can cite a few references about such bad silicone characteristics in traditional white LEDs.
Response: Thanks for the valuable comment. This is mainly due to the heat generation within the phosphor-silicone layer that was increased during aging of the WLEDs. We also have added relevant references to support this result.
In conclusion there are two almost controversial statements:
- In this work it was found that the failure of the QDs in the device is the main reason for degradation of the optical performances of the QDs-WLEDs.
- Besides from experiments it could be concluded that the decrease in luminous flux of the device was mainly due to the aging of the silicone.
May be authors can give some physical or chemical explanation of this effect origin.
Response: Thanks for the suggestion. In statement 1, we found that the degradation of QDs mainly affects the color quality (including CCT and CRI), as well as heat generation of WLEDs. In statement 2, we found that the degradation of silicone mainly affects the luminous flux, i.e., the optical energy power. Therefore, these two statements are drawn from different aspects, which is not conflict.
Reviewer 2 Report
1- The introduction part did not contain the different in this in compared to the previous research work
2- The focusing of figure 8 must be enhanced
3- The punctuation of the whole manuscript must be checked
Author Response
- The introduction part did not contain the different in this in compared to the previous research work
Response: Thanks for the valuable comment. We have polished the Introduction section to make it more innovative and concise.
- The focusing of figure 8 must be enhanced
Response: We have repainted Figure 8 to make it clearer.
- The punctuation of the whole manuscript must be checked
Response: We have checked the whole manuscript to avoid any punctuation errors.
Reviewer 3 Report
After carefully review the manuscript entitled: "Thermal and optical analysis of quantum dots-converted white LEDs under harsh environments", unfortunately, I cannot recommend this manuscript for publication in Electronics in the actual form.
After reading the complete text, it is difficult to extract what is the most important contribution of the work, which is not so facile to deduce.
Does the operational efficiency come from the silicon coverage, QDs, or the synergistic effect of the components?
In addition, a rigorous optical characterization of individual luminescent materials is not shown in the manuscript.
It is not clear in the actual form about what is the most important parameter to measure.
Silicon coverage has been used in other publications to prolong the stability of the luminescent QDs, for instance, perovskite nanocrystals. Therefore, authors should emphasize the role of the silicon into the intrinsic properties and stability of the QDs.
Minor errors are detailed along the text.
Author Response
After carefully review the manuscript entitled: "Thermal and optical analysis of quantum dots-converted white LEDs under harsh environments", unfortunately, I cannot recommend this manuscript for publication in Electronics in the actual form.
After reading the complete text, it is difficult to extract what is the most important contribution of the work, which is not so facile to deduce.
Does the operational efficiency come from the silicon coverage, QDs, or the synergistic effect of the components?
Response: Thanks for the critical comment. In this work, we found that the changes of optical parameters are mainly caused by the degradation of QDs, and the aging of QDs has different effects on the CRI and CCT. The analysis of the energy transfer process analysis shows that the decrease of luminous flux of QDs-WLEDs during the aging process was mainly caused by the aging of silicone. The results in this work have emphasis the importance of silicone degradation in the optical performance variation of QDs-WLEDs, which is easily to be ignored by peer researchers.
In addition, a rigorous optical characterization of individual luminescent materials is not shown in the manuscript.
It is not clear in the actual form about what is the most important parameter to measure.
Response: The most important parameter including CRI, CCT and luminous flux, and we have provided detailed characterization toward these parameters in this work.
Silicon coverage has been used in other publications to prolong the stability of the luminescent QDs, for instance, perovskite nanocrystals. Therefore, authors should emphasize the role of the silicon into the intrinsic properties and stability of the QDs.
Response: We agree that silicone encapsulation has been widely used in the QDs-WLEDs. However, most of the previous literatures ignored the effect of silicone degradation on the optical performance variation of QDs-WLEDs. Therefore, we conducted a comprehensive study towards this factor, and we think this study may propose different optimization strategies for optical quality and lifetime in the WLED design and manufacturing.
Round 2
Reviewer 3 Report
Congrats to the reviewers. Now, after checking the manuscript, the paper can be publishable in the actual form
Minor errors can be addressed along the text.
