The Diffusion of Triplet Excitons in Perylenediimide Derivative Crystals

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This study investigates the diffusion of triplet excitons in perylenediimide derivative (C5) crystals and their composites with ligand-functionalized quantum dots (Pe-QDs). The authors determined that triplet excitons in C5 diffuse with a coefficient, and approximately 79.5% of the excitons are captured by Pe-QDs under optimized conditions. These results demonstrate that triplet excitons can efficiently diffuse toward and transfer energy to quantum dots, indicating a promising route for enhanced triplet energy harvesting in silicon-based photovoltaic systems.

Comments

1. The resolution of Figure 1 needs improvement. This represents the most critical scheme for this study.
2. Add a discussion on page 4, lines, to discuss how the authors came up with the conclusions that C5-Pe-QDs (0.052%) based on the POM results, to the reader.

3. On page 5, line 138, please include references from a broader range of research groups, not only your own, to support your statements.

4. For Fs-tas, I believe they can explain the underlying principle of "target analysis" to the reader before jumping into the discussion. 
5. In general, the font sizes in all figures should be enlarged. 

Comments on the Quality of English Language

The English throughout the supplementary materials is generally clear, concise, and scientifically accurate. Sentences are well-structured, and technical terms are correctly used, enabling smooth reader comprehension. Occasional minor issues with spacing, article usage, and punctuation occur, but do not impede understanding. The manuscript's readership can be further improved by enhancing clarity through simplification of complex sentences and replacement of technical jargon with clearer terms, especially for an interdisciplinary audience. 

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

In the submitted manuscript, the authors report their study on the diffusion of triplet excitons in composites. They introduce varying concentrations of PbS quantum dots into perylenediimide crystals as traps to terminate triplet exciton diffusion. The diffusion coefficient and diffusion length of the triplet excitons were obtained through transient absorption measurements and modeling. Additionally, the authors simulated the diffusion trajectory and capture probability of triplet excitons within the composites. While substantial work has been done, there remain some issues and inconsistencies that need addressing:

1. In the introduction section on page 2, the authors present various experimental methods for studying triplet exciton diffusion. However, the discussion of these methods is incomplete. What are the advantages and disadvantages of each of these experimental techniques? Why did the authors ultimately choose transient absorption technique for studying triplet exciton diffusion? Could the authors elaborate further on this?
2. In the Materials and Methods section on page 3, the authors claim to replace the oleic acid ligands on the surface of the quantum dots (QDs) with Pe ligands. However, they do not explain why Pe ligands were chosen. What are the advantages of Pe ligands over the original oleic acid ligands?
3. In equation (5), the expression for the diffusion length includes a coefficient of 2. What does this coefficient represent? In many publications, the factor of 2 is omitted. Could the authors provide an explanation for this?
4. In both the main text and supplementary materials, the authors claim that the values obtained from the data of C5-Pe-QDs (0.010%) and C5-Pe-QDs (0.026%) exhibit greater errors compared to those of C5-Pe-QDs (0.052%), but the reasons for this are not explained. Could the authors provide a detailed explanation?
5. The authors assert that there is a linear relationship between the two variables in Figure 5, suggesting that Pe-QDs are well dispersed throughout the crystals. However, the authors do not provide an explanation for this. What is the connection between the linear relationship and the uniform distribution of quantum dots?
6. On page 3, the sentence "In recent years, for SF materials such as tetracene and perylenediimide derivative" contains an incorrect noun form. It should be corrected to "perylenediimide derivatives."
7. On page 3, the sentence "Therefore, we replaced the oleic acid ligands on the surface of the QDs with Pe ligands and subsequently incorporated the Pe-QDs into the precursor solution for C5 crystals formation" contains a grammatical flaw. It should be revised to "C5 crystal formation."
8. On page 8, the sentence "The transfer efficiency of T₁ excitons in the C5-Pe-QDs composites can up to approximately 129%-138%" is missing a verb. It should be corrected to "can reach up to."

Author Response

Please see the attachment.

Author Response File: Author Response.pdf