Modeling on Monolithic Integration Structure of AlGaN/InGaN/GaN High Electron Mobility Transistors and LEDs: 2DEG Density and Radiative Recombination
Round 1
Reviewer 1 Report
The Authors have reported an interesting numerical study of AlGaN/InGaN/GaN HEMTs and LEDs. Given the present interest in GaN-based devices, high-power electronics and high-frequency devices in general, their work represents a timely contribution to these interesting research fields. Although their work warrants publication in some form, the Authors must address the following issues before I can recommend the publication of this paper in Electronics.
1. There are many grammatical errors in this manuscript. For example, on page 4, line 115-116, AlGaN (not AlGaN), InGaN (not InGaN).....Moreover, the Authors should have punctuate all the equations. Please check their manuscript more carefully.
2. It is known that the effective mass of a GaN-based 2DEG could vary with increasing magnetic field. Please see D. R. Hang et al., Appl. Phys. Lett. 79, 66 (2001). The Authors may wish to comment on the significance of magnetic-field-induced non-parabolicity in quantum transport measurements.
3. As the Authors stated, the alloy composition x is an important parameter in their AlxGa1-xN layer. Could the Authors comment on the g-factor of their system? For example, please see K. S. Cho et al., J. Appl. Phys. 96, 7370 (2004). This is important for spin-related applications.
4. It is highly desirable to prepare devices on a Si substrate since they are fully compatible with existing Si CMOS tehcnology. It is well known that a lot of GaN-based devices are prepared on a sapphire substrate. The Authors should say something regarding this.
5. Finally, the Authors may wish to comment on whether their nice work could be applicable to the seminal work done by X. Liu et al., Advanced Science 9, 1903400 (2020).
Author Response
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Author Response.pdf
Reviewer 2 Report
1) Novelty compared to the existing works is Not clear in the abstract.
3) Highlight the main numerical finding in the abstract
4) List the advantages and disadvantages of the proposed method in the introduction.
5) In the introduction, write the main contributions with listing the advantages and disadvantages of the proposed method in form of bullets.
6) In figure 2, explain why with an increase of r, the concentration increases.
7) In figure 8, explain why there is a significant change at 0.505.
8) Fix typos, e.g., lines 223, 227, and 228 "Where" should be "where" with removing dots of their previous equations.
Comments for author File: Comments.pdf
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
In this manuscript, the authors investigated the 2DEG and 2DHG carrier densities in AlGaN/InGaN/GaN hetero structure via calculation and simulation. The physical model shown in this manuscript can be a guideline for monolithic integration of HEMT and LED. However, the manuscript includes some parts that should be revised before publication. The authors have to address the following questions and comments and modify their manuscript accordingly;
#1
In the abstract, the authors say that “… of AlGaN/InGaN/GaN HEMTs are established and verified with experimental data.” This statement could be misleading to the reader, since it could be taken to mean that the authors actually performed the experiment to verify the validity of the calculation results. Please rewrite the sentence to make it clear that the authors made comparisons with experimental results reported in other literature.
#2
In the abstract, the authors say that “2DEG density in AlGaN/InGaN/GaN HEMT is much higher than that in conventional AlGaN/GaN HEMTs, providing a higher driving current for LEDs.” However, alloy scattering in InGaN can drastically deteriorate the mobility of the carrier, which is shown in ref [16]. Note that even if the 2DEG concentration is increased by adopting InGaN channels, this does not necessarily lead to lower sheet resistance or higher current operation. I suggest that the description be changed to be fair.
#3
Please add references on Table 1.
#4
Some equation numbers show in main text are inappropriate. Please carefully recheck the numbers.
Author Response
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Author Response File: Author Response.pdf
Reviewer 4 Report
This work proposes a novel physical model on 2DEG density and the threshold voltage of AlGaN/InGaN/GaN HEMT, which is verified with experimental data from literatures. It is proved that the 2DEG density in AlGaN/InGaN/GaN HEMT is much higher than that in conventional AlGaN/GaN HEMTs. It warrants a publication if the following minor comments/suggestions are addressed.
1. The manuscript seems a complete work for modeling on 2DEG density and threshold voltage of AlGaN/InGaN/GaN HEMT without the third section. The third section provides an application for AlGaN/InGaN/GaN HEMT as LED driver and further proposed a model on radiative recombination rate of HEMT-LED monolithic integration structure, but the modeling on AlGaN/InGaN/GaN HEMT is valuable enough since the 2DEG density is much higher in this structure.
I suggest the authors leave out the third part and focus the topic on physical modeling on AlGaN/InGaN/GaN HEMT. Otherwise, the novelty of monolithic integration structure of HEMT and LED should be emphasized in the introduction section and Fig. 12 should be moved forward.
2. The third section lacks the calculation results of LED radiative recombination rate.
3. What is “2DHD” shorten for should be mentioned in the text.
4. The format of “FIG” in picture caption is inconsistent with “Fig” in the text.
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
thank you
