Role of Pyramidal Low-Dimensional Semiconductors in Advancing the Field of Optoelectronics

Round 1

Reviewer 1 Report

This article discusses the role of pyramidal low-dimensional semiconductors in advancing the field of optoelectronics. It provides a detailed analysis of the structures, preparation methods, band structures, electronic properties, and optoelectronic applications of pyramidal low-dimensional semiconductors. The article also explores the potential use of pyramidal semiconductor quantum dots for constructing optical quantum devices. It concludes with a summary of current challenges and suggestions for future research directions in this area. The review interestingly focuses on the pyramidal low-dimensional semiconductors and comprehensively introduce their wide applications. It covers many fields and could attract broad interest in optoelectronics. With these regards, the review can be suggested for publication. Some minor revisions are suggested before publication:

1.     It would be nice if the authors provide tables to summarize the plenty information.

2.     The length of the review can be shortened to read easily.

3.     Some important references including quantum dots and other morphological with pyramidal and advanced morphology observations technique are suggested for reference, such as:

 S-Scheme Heterojunction of Cu2O Polytope-Modified BiOI Sheet for Efficient Visible-Light-Driven CO2 Conversion under Water Vapor[J]. Acta Phys. -Chim. Sin. 2023, 39(6), 2210003.

Colloidal Quantum Dot Solids with a Diminished Epitaxial PbI2 Matrix for Efficient Infrared Solar Cells. Acta Phys. -Chim. Sin. 2023, 39, 2210002.

Four-Dimensional Scanning Transmission Electron Microscopy: From Material Microstructures to Physicochemical Properties[J]. Acta Phys. -Chim. Sin. 2023, 39(3), 2210017

Progress in the Development of Colloidal Quantum Well Light-Emitting Diodes[J]. Acta Phys. -Chim. Sin., 2022, 38(12): 2204052.

Morphologically-tunable TiO2 nanorod film with high energy facets: green synthesis, growth mechanism and photocatalytic activity，Nanoscale, 2012, 4, 5023-5030.

Hydrothermal growth of layered titanate nanosheet arrays on titanium foil and their topotactic transformation to heterostructured TiO2 photocatalysts，J. Phys. Chem. C, 2011, 115, 22276-22285.

Minor editing of English language required

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

Title: Role of pyramidal low-dimensional semiconductors in advancing the field of optoelectronics

Authors: Ao Jiang, Shibo Xing, Haowei Lin, Qing Chen, and Mingxuan Li

In the submitted manuscript, the authors review pyramidal-shaped low-dimensional semiconductor heterostructures - they focus on heterostructures with 3D and 2D spatial confinement and discuss several material composition systems based on II-VI, III-V, and IV compounds of the periodic table.

Paper organization

The paper has 35 pages of text (in the format for the review process) and is structured into 5 sections. In the first section, the authors present a brief introduction focused on nanotechnology and nanomaterials in general. In section 2, they discuss several heterostructures based on different material compositions and their associated growth techniques. Section 3 focuses on theoretical description (k.p approximation). Chapter 4 focuses on excitonic state formation and optical emission changes induced by quantum confinement. Finally, in section 5, they discuss some consequences for the heterostructure applications, namely for solar cell efficiency enhancement, photodetection, chemistry, and light emission.

Topic of the review

The authors introduce the work by the motivation of low-dimensional semiconductor heterostructures through the definition of nanotechnology, they mention that properties of the low-dimensional materials are modified with respect to bulk contra parts due to their dimensional constraints which gives access to tailoring their characteristics - for example by changing their shape.

Unfortunately, the authors select pyramidal low-dimensional structures without the motivation of this choice. Since this shape seems to be relevant for this review (“pyramidal” in the title), could the authors add a motivation for this specific choice? As a reader, I would expect to find in this work a comparison to different shapes. Do pyramidal structures bring a fundamental/technological benefit over other shapes?

Moreover, the role of the “pyramidal” semiconductor nano-structures is not evident to me through the presented work, despite I read it carefully and made extensive notes while reading. Could the authors strengthen and organize the arguments about the role, i.e. benefits and disadvantages, for the selected applications they decided to discuss? I believe a reader would greatly benefit from it.

I am also wondering, how the authors selected the papers for this review – typically, in many applications in literature, the shape of the nanostructure is not discussed. Could authors also briefly comment on this?

Decision

This work is submitted as a review paper, therefore, it should contain two important aspects: (i) it should discuss the state-of-the-art situation of the subject, and (ii) it should have a clear structure allowing quick orientation of no experts in the field – below, I comment on these two points briefly.

Because, in my opinion, these two points are not fulfilled in the submitted work, and because the subject of the review is not well motivated, I do not recommend publication in the present form. 

 (i) State-of-art

I disagree that nanotechnology is an emerging research field, as the authors state in line 30. Maybe the authors would like to rephrase this statement, especially taking into account that around 8% of their references (21 from 291) are dated back to the 1990s. I would call nanotechnology a fully established, still dynamically growing field with technological overlap even to everyday life! In fact, this impact is also appreciated by the authors in line 37, where they state “it has had a great impact on socioeconomic development, scientific and technological progress, and advancing the quality of human life.”

Surprisingly, between the 69 references from 2020-2024, I miss important milestones. To give some examples from quantum communication applications, such sources have been employed for quantum-key distribution [Basset, Quantum Sci. Technol. 8 025002 (2023)], serve as deterministic single-photon sources [Tomm, Nature Nanotechnology 16,399 (2021)] allows to produce complex entangled quantum states useful for quantum applications [Coste, Nature Photonics 17, 582 (2023), Schwartz, Science 354, 434 (2016)], or have been employed in simple photonic quantum computer [Maring, arxiv 2306.00874, 2023].

(ii) Structure

From the reading, I got a strong impression that the presented text is more of a literature review than a knowledge review. This is not bad in principle, however, it brings a text structure of the form: Authors1 did this. Authors2 did that. This structure significantly complicates orientation in the text because it gives an idea of who did what, but not where the field is heading and what obstacles overcame – information expected from a review article. Also, it does not allow to distinguish between field direction and detour done by individual researchers. If rewritten from the perspective of field development, I believe that the story could have a higher impact since readers would learn the status of the field more efficiently.

 I also suggest using extra text structuring for different material compounds in section 2 – either paragraphs or subsections. Now, there are several material structures listed in a single paragraph (AlGaAs structures start at line 180, InP at line 192, II-VI materials start at 196, nitrides at 204, PbSe at line 230). For example, in section 2, I strongly recommend structuring the text under at least three extra headers associated with II-VI, III-V, and IV materials.

I also want to turn the attention of the authors to the unequal depth of details in crystallographic morphology discussed in section 2. In my opinion, the authors in excessive detail introduce surface formation in the case of SiGe and InAs quantum dots, supported by Figs. 2 and 3. In contrast, the surface morphology of the remaining material structures is typically discussed in one line. Could the authors explain why the level of detail is not comparable? Is this because of missing research or due to similarities between the structures and their formation? Additionally, is the level of detail for SiGe and InAs important? If the specific surface orientation does not play a role (if I am correct, the role of the surface is not discussed in the text), then it seems like a technicality to me, distracting from the more general picture the authors probably want to draw.

Title and introduction:

Title: The authors decided to name the work “Role of pyramidal low-dimensional semiconductors in advancing the field of optoelectronics”.

(i) “Low-dimensional semiconductors” suggests focusing on any semiconductors with at least one spatial dimension below a specific threshold, explicitly including also 2D materials. This is, however, not the subject of the work, where the authors focus only on 0D and 1D structures.

(ii)  “Role in advancing” suggests that the focus will be on the benefits of using such low-dimensional semiconductors and quantification of their impact on the optoelectronics, i.e. comparison if they are used vs if they are not used.

Introduction: The presented introduction contains repetitiveness in the first paragraph where it several times mentions “multidisciplinary”. Also, in my opinion, the focus should be brought much more from general statements about nanotechnology to pyramidal structures and the motivation why the authors favor pyramidal structures over other shapes. Turning the introduction this way would greatly motivate the following sections and the reader would benefit greatly from the information on why pyramidal structures are of the interest of the field.

Figures:

Please, check the quality of all figures! In the review document, all figures are pixelated.

Some figures are inadequate! For example, Fig. 10 - why do authors use graphene as an example for k.p approximation? The work is focused on pyramidal low-dimensional semiconductors – graphene, being 2D monolayer semimetal, is definitely not from this family of materials!

 Figures are often not well connected to the text:

• Fig. 1: Is this Figure necessary? There are just geometrical shapes – maybe you could use experimentally obtained figures of realistic structures instead.

• Fig. 5 shows steps in MOVCD and MBE depositions. However, the text does not mention these steps. I suggest removing the figure!

•  Fig. 8b: there are several figures which I do not find commented on in the text.

• Fig. 10: Authors show a figure corresponding to graphene. This figure has to be removed because this study is not about 2D materials or semimetals, but about 0D and 1D pyramidal semiconductors!! Moreover, the figure has 6 panels, where none is discussed in the text!

• Fig. 11: Panel e) needs to come first! Moreover, the statement “It was also found that the perpendicular quantum wire barrier simultaneously expanded the energy separation between the s- and p-states, whilst reducing the sensitivity of the s-state energy to size fluctuations” is not obvious from the figure. Change the figure or clarify in the text better. Now, I do not see value in having the figure there!

• Fig. 12: Panel a) not needed, pyramid is a common shape. Moreover, panel b) shows the same information but much more clearly! Add to the caption, along which direction the electric and magnetic field is applied since it is highly relevant. Also, you should add dimensions of the structure (either to figure or to caption). I also wonder with respect to which energy the y-axis in panels c) and d) is shown – comment on that.

•  Fig. 13: What does this figure show except pyramids from atoms? Add to the caption what the triangles in the bottom panels represent. Or remove! Moreover, in this section, I would expect figures showing energy structures/levels or density of states as a function of some internal or external properties, not just a structural structure from atoms.

• Fig. 15: You show the wave function of the effective electron formed from all electrons in the quantum dot. Electrons are present everywhere in the structure! You probably want to write “electron-wavefunction” instead of “electrons”. Similarly for holes. Also, I recommend to refer to the individual panels from the text!

• Fig. 16: The authors write: “Illustration of key dynamic processes in a quantum dot and in a related pump-probe 762 transient absorption measurement.” However, they do not comment on the dynamic processes, that are numbered in the figure as 1-4! Panel c) shows strongly bound and weakly bound excitons (no need for the word “photogenerated” – remove it).

• Fig 25 overflows text margins

Selection of material compositions

The authors give an exhausting list of different material systems prepared as pyramidal low-dimensional heterostructures. If I am correct, they mention all material combinations except heterostructures based on GaP - despite these structures, according to literature, are examples of pyramidal low-dimensional structures, too. Could authors comment on why they omit this structure or potentially include this material structure in the text?

Here are several studies as an example:

PRB 100, 115424 (2019); Light: Science & Applications 10, 125 (2021); Appl. Phys. Lett. 102, 123102 (2013); PRB 100, 195407 (2019)

Other (smaller) comments:

There are mistakes in the in-text referencing using first author reference. Check and correct the references: For example, in line 263, you should write “reviews by Kapon and Pelucchi et al. [92,93]”. Instead of “reviews by Kapon and Pelucchi [92,93]”. Similarly, in line 281, “Watanabe et al. prepared …” instead of “Watanabe prepared”.

Line 14: grammatical error: authors want to write “have been favored”

Line 34: Replace “scientific issues” with “challenges”  - you do not want to start your review with negative connotations induced by the word “issue”.

Line 49: why do authors use “special effects” – they are not special, but they are manifested in the dimensionality at least in one dimension and are reduced to (or below) Bohr exciton radius level.

Line 51: Is there a reason why authors do not list also optical properties in the list? Later, in the manuscript, they talk also about them.

Lines 63-64: The sentence: “In general, spherical or quasi-spherical QD is used to prepare II-VI, IV-VI, and III-V semiconductors” does not make sense. The shapes of heterostructures are not responsible for the compound composition!

Line 69: What do authors mean by “exhibit poor stabilities”? It is very unclear.

Lines 82-84: Authors state: “Indeed, a large number of studies have shown that these quasi-one-dimensional nanomaterials and structures have promising applications in nano-optoelectronic and electronic devices’. Such a statement requires references!

Lines 84-86: Authors write: “To date, PSNRs and PSNWRs have been applied in the fields of photodetectors and solar cells, and are related to the strong light absorption effects of one- dimensional pyramidal nanomaterials [51]”. The phrasing “to date” is not justified by a 10-year-old reference [51]!

Lines 91-93: The sentence “the orientation of 91 each crystal plane in the pyramidal structure is different because of the different components and manufacturing processes involved in the preparation of semiconductor materials” is unclear.

Lines 96-97: “Taking PSNRs as an example, although these species do not possess the typical characteristics of pyramidal low-dimensional semiconductors in the traditional sense”. Then, why do you use it as an example, if it is not traditional? Especially, if in a few lines lower, you turn the attention to PSQDs!

Line 116: To what do you refer by simplest?

Line 124: Do you mean

“as their volume increases”?

Line 125: Incorrect verb? “These pyramidal growth islands get/take the shape … ”

Line 137: This sentence does not make sense. SiGe QDs are also PSQDs.

Line 138: The transition using “however” is wrong here. Use only “Researchers have …”

Line 141: InAs/GaAs structures have (not expected as written by the authors) application potential.

Lines 151-152: “the work of Xu’s group being the most influential [73].” I am skeptical if the work is the most influential (it got around 70 citations in almost 20 years). I suggest removing “the work of Xu’s group being the most influential” and using the reference directly after “pyramidal QDs”.

Line 238: Here, you refer to observations/conclusions of others. Thus, replace results with observations/reports to distinguish them from your results.

Lines 278-279: Could authors revisit the sentence “and this approach is applicable not only for lattice mismatch but also for lattice matching” – it does not make sense to me.

Line 470: The symbol Un is not defined.

Lines 670-674: Atoms in the nano-structures are still held together by covalent bonds, therefore the electrons have to be everywhere in the volume of the structure. The authors mean here “effective electron wavefunction” which can be used for molecule-like orbital description. Such wavefunction is located for small QD in the center, and at the top for big QD. Replace electrons by electron-wave function (same for holes).

 Line 722: there are other external factors – strain, temperature, capping layer, etc. Could you add references?

Lines 740-744: This text could be split into two sentences.

Line 749: Here, the authors probably mean “the excitonic behavior” instead of "exciton behavior".

Line 751: What do the authors mean by type II? It is not defined.

Line 783: Typo: Start the sentence with the capital letter “Additionally, …”

Line 797: Extra “of” in “biexciton binding energy of changed …”

Line 799: There are modern papers where the piezo-electric effect is used to manipulate the splitting [for example PRL 109 147401 (2012)]

Line 971: Replace “the” by “with” in the following text: “obtained with 180/25…”

Lines 1141-1142: I discourage the following formulation “among which EL is associated mainly with light-emitting diodes (LEDs) and PL is mainly associated with lasers” because it is not true. Photoluminescence is not related to lasers – PL is the photon response of a material on light illumination (not necessarily by laser). If the authors meant that the laser works on PL mechanism – it is also not valid, because there are many lasers such as semiconductor-diode lasers which work on the principle of electroluminescence.

Line 1143: What do the authors mean by “similar structure” in this context?

Line 1144: I would use “QD-based LEDs have …”

Line 1157: Probably a typo – do the authors mean “during the investigation…”?

Line 1160: I strongly suggest replacing “realized in an LED” with “realized in a p-i-n junction” since the p-i-n junction is the physical configuration of electric gates, and the LED is then the device using a p-i-n junction to emit light.

Line 1164: Also here, replace “LED” with “p-i-n junction” for the same reason as above.

Line 1166: I think that “it is expected that this system could be applied to integrated photonic circuits in the near future” is not valid. Such devices have been already integrated. Not sure what exactly the authors have in mind here, but I can suggest for example this reference [Nature Communications 7, 10387 (2016)]

Lines 1175-1176: No, the laser is not a PL phenomenon. A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation (Wikipedia). Authors probably wanted to write: “PL is a phenomenon where electrons of atoms and molecules excited into higher energy levels (for example by laser light) recombine to their ground state via spontaneously releasing photons.”

Lines 1219-1221: The statement “In addition, Goshima et al. studied the Rabi oscillation properties of excitons in single truncated pyramidal InAs/GaAs QDs [262], and discovered that the π pulse can be exploited as a one-bit rotating optical pulse for quantum computing” follows directly discussion about QD-based lasers. However, the statement is not in addition to lasers, but it is a disconnected fact, that QD levels can be controlled resonantly, which is exhibited as Rabi oscillations.

Line 1257: Do the authors mean “unidirectionally emitting QDs”?

Line 1324: Could the authors explain what they mean by “poor stability”?

Line 1334: Replace “PSNRs (PSNWRs)” with “PSNRs and PSNWRs”.

Lines 1347-1348: Please rephrase the sentence “Furthermore, utilizing the excellent properties of Rabi oscillations in PSQD lasers is another potential method to accomplish quantum computing”. (i) Rabi oscillations are not property but manifestation of coherent manipulation of state populations of two energy level systems. (ii) PSQD lasers are lasers where a layer (layers) of QDs are used as a frequency-continuous (over some bandwidth) medium – I do not see how this medium (in the general continuum of states) could be driven coherently, i.e., without interacting with the environment on each level system (each QD in this case) level. (iii) Can authors specify the connection between Rabi oscillations and quantum computing – I do not see it despite my work in quantum optics and photon manipulation.

Lines 278-279: Could authors revisit the sentence “and this approach is applicable not only for lattice mismatch but also for lattice matching” – it does not make sense to me.

Line 470: The symbol Un is not defined.

Lines 670-674: Atoms in the nano-structures are still held together by covalent bonds, therefore the electrons have to be everywhere in the volume of the structure. The authors mean here “effective electron wavefunction” which can be used for molecule-like orbital description. Such wavefunction is located for small QD in the center, and at the top for big QD. Replace electrons by electron-wave function (same for holes).

Line 722: there are other external factors – strain, temperature, capping layer, etc. Could you add references?

Lines 740-744: This text could be split into two sentences.

Line 749: Here, the authors probably mean “the excitonic behavior”

Line 751: What do the authors mean by type II? It is not defined.

Line 783: Typo: Start the sentence with the capital letter “Additionally, …”

Line 797: Extra “of” in “biexciton binding energy of changed …”

Line 799: There are modern papers where the piezo-electric effect is used to manipulate the splitting [for example PRL 109 147401 (2012); PRB 97, 245314 (2018).

Line 971: Replace “the” by “with” in the following text: “obtained with 180/25…”

Lines 1141-1142: I discourage the following formulation “among which EL is associated mainly with light-emitting diodes (LEDs) and PL is mainly associated with lasers” because it is not true. Photoluminescence is not related to lasers – it is photon emission stimulated by light (not necessarily by laser). If the authors meant that the laser works on PL mechanism – it is also not valid, because there are many lasers such as semiconductor-diode lasers which work on the principle of electroluminescence.

Line 1143: What do the authors mean by “similar structure” in this context?

Line 1144: I would use “QD-based LEDs have …”

Line 1157: Probably a typo – do the authors mean “during the investigation…”?

Line 1160: I strongly suggest replacing “realized in an LED” with “realized in a p-i-n junction” since the p-i-n junction is the physical configuration of electric gates, and the LED is then the device using a p-i-n junction to emit light.

Line 1164: Also here, replace “LED” with “p-i-n junction” for the same reason as above.

Line 1166: I think that “it is expected that this system could be applied to integrated photonic circuits in the near future” is not valid. Such devices have been already integrated. Not sure what exactly the authors have in mind here, but I can suggest for example this reference [Nature Communications 7, 10387 (2016)]

Lines 1175-1176: No, the laser is not a PL phenomenon. A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation (Wikipedia). Authors probably wanted to write: “PL is a phenomenon where electrons of atoms and molecules excited into higher energy levels (for example by laser light) recombine to their ground state via spontaneously releasing photons.”

Lines 1219-1221: The statement “In addition, Goshima et al. studied the Rabi oscillation properties of excitons in single truncated pyramidal InAs/GaAs QDs [262], and discovered that the π pulse can be exploited as a one-bit rotating optical pulse for quantum computing” follows directly discussion about QD-based lasers. However, the statement is not in addition to lasers, but it is a disconnected fact, that QD levels can be controlled resonantly, which is exhibited as Rabi oscillations.

Line 1257: Do the authors mean “unidirectionally emitting QDs”?

Line 1324: Could the authors explain what they mean by “poor stability”?

Line 1334: Replace “PSNRs (PSNWRs)” with “PSNRs and PSNWRs”.

Lines 1347-1348: Please rephrase the sentence “Furthermore, utilizing the excellent properties of Rabi oscillations in PSQD lasers is another potential method to accomplish quantum computing”. (i) Rabi oscillations are not property but manifestation of coherent manipulation of state populations of two energy level systems. (ii) PSQD lasers are lasers where a layer (layers) of QDs are used as a frequency-continuous (over some bandwidth) medium – I do not see how this continuum could be driven coherently, i.e., without interacting with the environment on each level system level. (iii) Can authors specify the connection between Rabi oscillations and quantum computing – I do not see it despite my work in quantum optics and photon manipulation.

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

The review article requires significant revisions in its language to meet publishing standards.

The introduction notably lacks emphasis on the importance of pyramidal structure and its technological relevance.

The figures are inadequately described.

Furthermore, there is a lack of outlook, with the content merely providing a mere documentation of relevant articles in the field.

Major editing is required.

Author Response

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Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

Title: Role of pyramidal low-dimensional semiconductors in advancing the field of optoelectronics

Authors: Ao Jiang, Shibo Xing, Haowei Lin, Qing Chen, and Mingxuan Li

In the resubmitted review, the authors sufficiently address most of my comments. By introducing a finer manuscript structure, the text became better readable, allowing easier navigation. Also, the selection of figures improved – supporting the reviewed topic now better.

However, the manuscript still lacks clear motivation in the introduction of why the authors selected pyramidal nanostructures. The authors added Table 1, where they compare several morphologies, and show photoluminescence quantum yields. I encourage authors to discuss (also in the text) this difference and (at least from the table suggested) the benefit of pyramidal structures in this specific aspect. Ideally, if they have more benefits in mind, mention them as well.

If the choice of pyramidal morphology is motivated in the (beginning of the) manuscript and the other comments (below) arising from the text changes the authors made are implemented, I will consider supporting publication.

More comments:

Authors response 1: The influence of material microstructure on properties is one of the core domains of the material science and engineering, and material morphology is the key factor. The study of material morphology has become an important direction for the development of material science. Based on material thermodynamics, kinetics, and crystallography, the main content of material morphology includes the formation of material structures and effects of structures on material properties. However, so far, material morphology has not formed a complete theoretical system, and the related work needs to be further systematized. With the development of material science, there are various material systems formed. It is very necessary to classify and summarize them. In view of the above reasons, we try to write an article on the morphology and properties of materials. Because there are many factors that affect the morphology and properties of materials, it is a huge challenge to write such a review. We hope to attract more researchers' attention to material morphology by writing a review in this field. In fact, some research articles and reviews on material morphology have been published in recent years, such as:

(ⅰ) Mishra, Nimai, V. G. Vasavi Dutt, and Milena P. Arciniegas. "Recent progress on metal chalcogenide semiconductor tetrapod-shaped colloidal nanocrystals and their applications in optoelectronics." Chemistry of Materials 31.22 (2019): 9216-9242.

(ⅱ) Liu, Yincheng, Sumanta Bose, and Weijun Fan. "Effect of size and shape on electronic and optical properties of CdSe quantum dots." Optik 155 (2018): 242-250.

(ⅲ) Liang, Litao, and Wenfang Xie. "Influence of the shape of quantum dots on their optical absorptions." Physica B: Condensed Matter 462 (2015): 15-17.

Because the introduction is not clear, we rewrite the introduction and compare the luminescence properties of low-dimensional materials (quantum dots) with different morphologies in Table 1. 

Referee: Authors mention in the cover letter review papers that are not listed in the manuscript. I think readers would strongly benefit from having them included. Please, incorporate them into the manuscript text.

Authors response 2: Certainly, it is a good idea to compare the advantages and disadvantages of different material systems and shapes in the field of optoelectronics. However, as we discussed in Part (1), because material morphology don’t possess a very mature theory, there is still a lot of research work to be carried out. Therefore, we give priority to expressing the application of a shape here. In addition, we believe that with the development of materials genome engineering and energy band engineering, the application value of material systems with different morphologies will be further explored.

Referee: Please, write this motivation clearly in the introduction, and abstract, and potentially repeat your vision for the development of different morphologies also in conclusions.

Authors response 10: With regard to the title, our initial purpose is to discuss the application of pyramidal low-dimensional materials in various fields of optoelectronics. From the current development situation, pyramidal quantum dots with core-shell structure may have great application potential in photocatalyst and solar cells. Patterned pyramidal quantum dots also have certain application value in optical quantum information. Pyramidal nanorods have potential application value in photodetectors and solar cells, whereas more quantitative researches need to be further studied.

Referee: It would be interesting for readers to learn this general objective about where which material is useful already in the beginning - then, it would attract readers' attention and build interest in the details presented later in the text.

Small comments:

• Fig. 15 overflows margins
• Line 1234: I recommend removing ", releasing photons via spontaneous emission" from "Lasers are another luminescent device that excite the electrons of atoms and molecules to higher energy levels, releasing photons via spontaneous emission." since the authors continue in the paragraph by discussion of lasers, not of spontaneous emission.
• 1369: I think the authors mean here "improve their room temperature photoelectric performances"

Author Response

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Reviewer 3 Report

The comments are addressed in the present version and I have no reservation in recommendation. 

Can be improved. 

Author Response

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