Silver-Nanowire-Based Localized-Surface-Plasmon-Assisted Transparent Conducting Electrode for High-Efficiency Light-Emitting Diode

Round 1

Reviewer 1 Report

This manuscript can’t be recommended to publish in this journal. The reasons are as follows:

1. No data about LED devices, such as IV, EQE and power efficiency.
2. Too similar contents with authors’ previous work [1].
3. Figure 2(b) has already been presented in [1]. Same SEM images.

[1] Kim, J. Y., Cho, Y. H., Chung, T. H., Jang, Y. J., Kim, W. H., Bang, S., ... & Kwon, M. K. (2020). Localized surface plasmon-enhanced transparent conducting electrode for high-efficiency light emitting diode. Materials Letters, 271, 127790.  

Author Response

We greatly appreciate your time and efforts to improve the quality of paper. We revised our paper based on your comment and suggestion.

Author Response File: Author Response.docx

Reviewer 2 Report

In this manuscript the authors proposed a new method of using silver-nanowires in combination with silver nanoparticles as a promising candidate for transparent conducting electrodes. The authors demonstrated increased PL intensity for an LED structure with a 45nm p-GaN layer, while such an improvement was not observed with a p-GaN layer of 120nm. Authors also performed FDTD simulation to strengthen their assumption about the plasmonic effect of the silver nanowire and nanoparticles.  The paper is well organized and contains interesting results. I recommend publication after some changes.

1. Authors have used Ref. 14 as a backbone for some of their assumptions. For example, improving the IQE utilizing the Silver NWs and Silver NPs. Ref 14, has no IQE measurement data. It is only room temperature (RT) PL intensity comparison. A RT-PL intensity/ Low temperature (LT) intensity is required to have a strong idea about the IQE measurement. PL intensity at RT might increase twice this means just as a rule of thumb, the real IQE should be very low (below 50%). Starting with an LED with poor quality (Low IQE) and show PL intensity improvement at RT is not that interesting. I recommend the authors to measure the IQE and then compare the effect of Ag-NWs and AG-NPs.
2. Improving the IQE and lifetime reduction by virtue of plasmonics can be related to increasing the radiative lifetime and Purcell factor. Can author comment on the Purcell enhancement factor for their structures? For example, please see the followings
   2015. Nami, M. and Feezell, D., 2015. Optical properties of Ag-coated GaN/InGaN axial and core–shell nanowire light-emitting diodes. Journal of Optics (Online), 17(2).
   2016. Novotny L and Hecht B 2006 Principles of Nano-Optics(Cambridge: Cambridge University Press) chapter 8.
3. One of the main issues in Ag-based plasmonic structures is the silver oxidation. This process ruins if not degrades the plasmonic properties of silver. Can authors comment on how they were able to manage this issue?
4. Can authors show the L-J-V for two structures one with ITO and one with Ag-NWs+NPs?
5. The thickness of quantum well/barrier should be 3nm/7 nm instead of 30/70 nm. Please fix it.
6. The size of the Ag NPs is 35±20 nm. This is a very large size variance. Can authors comment on this?
7. The thickness of the p-GaN usually has a periodic influence on light extraction efficiency. Have authors tested other thicknesses of the p-GaN layer? Please see below:
   1. Choi, Y.H., Ryu, G.H. and Ryu, H.Y., Numerical Investigation of Purcell Enhancement of the Internal Quantum Efficiency of GaN-based Green LED Structures.
   2. Nami, M. and Feezell, D.F., 2014. Optical Properties of Plasmonic Light-Emitting Diodes Based on Flip-Chip III-nitride Core-Shell Nanowires. Optics express, 22(24), pp.29445-29455.
8. The word thickness in figure 4, “Thickness between NW and NP” has to be changed to spacing or distance.
9. Can authors simulate the absorption spectrum (or Optical density spectrum) for the both Ag-NWs and Ag-NPs and Ag NWs+Ag NPs?

Author Response

We greatly appreciate your time and efforts to improve the quality of paper. We revised our paper based on your comment and suggestion.

Author Response File: Author Response.docx

Reviewer 3 Report

The paper "Silver-Nanowire-Based Localized-Surface-Plasmon-Assisted Transparent Conducting Electrode for High-Efficiency Light-Emitting Diode" reported about ITO-free Ag NW+NP SP-enhanced TCEs. The IQE and the LEE was improved by QW–LSP coupling and LSP–TM light coupling, respectively. The LED efficiency was enhanced by combination between NWs and NPs. However, the manusciprt has a lack of experiments for confirming their opinions. This manuscript can be published in the journal "Applied Sciences" after minor revision.

1. English writing should be modified. I would suggest the author's review again to correct for awkward phrasing and language. And, please double check the typos.
2. The reveiwer thinks that the authors should fulfill more material analyses including XRD, EDS and so on.
3. The authors should obtain the experimental results which are related with the simulation data in Figure 4.
4. The reveiwer want to confirm the PL images of device that derived the graphes in Figure 5.
5. The reviewer thinks the authors should talk about more papers about AgNW with LEDs in Introduction part with reference. It can improve this paper’s impact. The reviewer recommends some state-of-arts papers in high-impact journals. In addition to the recommended papers, there are more papers about that, so find and add more.

Advanced Materials 30.28 (2018): 180064

Scientific reports 5.1 (2015): 1-11.

Comments for author File: Comments.docx

Author Response

We greatly appreciate your time and efforts to improve the quality of paper. We revised our paper based on your comment and suggestion.

Author Response File: Author Response.docx

Reviewer 4 Report

The authors have demonstrated the effectiveness of adding Ag nanoparticles to nanowires for improved light extraction efficiency of TCEs through the activation of localized surface plasmons. The work is promising and paves way for exploring the combination of nanoparticles and nanowires in different ways to exploit the properties of the surface plasmons. The manuscript is recommended for publication with the following minor revisions.

• The authors are recommended to report roughness information of the metal layers to better understand the scattering effect of the surface plasmons.
• FE-SEM images of 35 +/- 10 nm and 100 +/-  20 nm with both scale bars 500nm and 2μm are recommended to obtain a perspective of the size
• Figure 2 caption doesn’t mention (c)  although there is a figure present.

Author Response

We greatly appreciate your time and efforts to improve the quality of paper. We revised our paper based on your comment and suggestion.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

I think the revised manuscript has been strongly improved. It can be accepted.