Comparison of the Optical and Electrical Properties of Al-Doped ZnO Films Using a Lorentz Model
Round 1
Reviewer 1 Report
This study investigates the optical and electrical properties of Al-doped ZnO (AZO) films. The work investigates Al doping under various conditions: oxygen partial pressure, concentration and post annealing temperature. This investigation of the optical properties uses a parametric model with two Lorenz oscillators. Conductive properties are investigated by Hall effect measurements obtained with spectroscopic ellipsometry.
The paper is well written and easy to follow. The theoretical background in the introduction is well explained, but could be improved with a more detailed description.
The mathematical models are well derived and explained, and are consistent with the experimental results.
The conclusion sums up the work very well, but could be improved with a comparison with other solutions reported in literature.
There are some minor text errors to be considered. For example, Line 12 (Abstract) states: "each film is successfully analyzed its electrical and optical properties"—explain that the properties were analyzed, or line 32—try rephrasing "highly visibly transparent", etc.
Define the acronym AFM on line 95
Place the reference on line 104
Lines 113 and 121, type the word "and" on the line after the equation
Lines 108, 118, 350, 373 paragraphs continuing the sentence after the equation should not be indented.
Figure 6, yellow text on the grayish-white background, i.e., Figure 6b,c is not visible.
Author Response
Comments and Suggestions for Authors
This study investigates the optical and electrical properties of Al-doped ZnO (AZO) films. The work investigates Al doping under various conditions: oxygen partial pressure, concentration and post annealing temperature. This investigation of the optical properties uses a parametric model with two Lorenz oscillators. Conductive properties are investigated by Hall effect measurements obtained with spectroscopic ellipsometry.
The paper is well written and easy to follow. The theoretical background in the introduction is well explained, but could be improved with a more detailed description.
The mathematical models are well derived and explained, and are consistent with the experimental results.
The conclusion sums up the work very well, but could be improved with a comparison with other solutions reported in literature.
Response: We added two contents to the manuscript, “Chinta et al. has also found the NHall value from 4.86 × 1019 to 2.99 × 1020 cm−3 and the Nopt value from 5.85 × 1019 to 2.29 × 1020 cm−3 for constant m* when the ZnO films were doped by Al from 0 to 10 at.% [43].”; and, “Knoops et al. also studied the μopt and μHall values of the deposited 150-nm-thickness AZO film were approximately 17 and 12 cm2/Vs, respectively [46].” for comparisons.
There are some minor text errors to be considered. For example, Line 12 (Abstract) states: "each film is successfully analyzed its electrical and optical properties"−explain that the properties were analyzed, or line 32—try rephrasing "highly visibly transparent", etc.
Response: Rephrasing Line 12: The electrical and optical properties of each film are successfully analyzed by…...
Rephrasing line 32: highly visible transparent
Define the acronym AFM on line 95
Response: Amended as advised.
Place the reference on line 104
Response: The reference of the following content is also [20], so the “[]” should be canceled.
Lines 113 and 121, type the word "and" on the line after the equation
Response: The word “and” has been changed positions before the equations.
Lines 108, 118, 350, 373 paragraphs continuing the sentence after the equation should not be indented.
Response: Those paragraphs have been revised.
Figure 6, yellow text on the grayish-white background, i.e. Figure 6b,c is not visible
Response: We changed the color of annotated words to red.
Reviewer 2 Report
The manuscript is too long. The main subject as declared in title and abstract is comparing the resistivity, mobility and free carrier concentration estimated by electrical and optical methods (Hall effect and ellipsometry). This part of manuscript is new and interesting. The rest of the manuscript is less interesting and part of it could be omitted. In particularly:
The influence of oxygen partial pressure and Al doping, authors already published.
Experimental setup is already described in previously published articles.
The model of measured AZO thin films for fitting the ellipsometry measurements and parametric model containing two Lorentz oscillators in data analysis was described in previous published articles by the same authors.
The deposition method is interesting, but the setup is unique, and parameters devoted to it have limited value (for example H value in Table 1)
Join the all above unnecessary items resulted in incomplete information and lack of proper discussion the results. However, it is on the authors to keep the concept as it is.
What in my opinion should be corrected are items listed below:
Experimental data are missing.
Annealing was done in air?
AZO used for annealing was 1.5% Al, but what was PO2?
Some cumbersome statements should be reformulated or omitted
“In this comparison, the spring represents the electrostatic force on the electron caused by all the other electrons and nuclei in the solid, and the dissipative force represents the energy loss due to the emission of a photon. This classical model treats the electron as a particle that has mass orbits with a given trajectory and a certain amount of kinetic energy “
I would say that emission of photons is not a “classical “effect. The BM effect is a consequence of Pauli exclusion principle.
The worst part are Figures.
Figure 4c,d the structure of AZO—what is the concentration of Al?
Figure 5 It is not clear are the data on the axes connected or not. E.g. for example, grain size vs Al concentration—were the samples deposited at same PO2 or each point correspond to different PO2. The same for grain size vs temperature of annealing. If the PO2 is the same for these two sets of dana, Figure 5 should be divided into 3 figures. size vs temp. annealing, size vs. oxygen conc. and size vs. Al concentration. If not, the additional explanation to the graphs should be written.
What is the concentration of Al in “AZO films “?
(The value for Al% is given on page 9, while Figures 4,5 are on page 5)
Author Response
Response Reviewer 2:
Comments and Suggestions for Authors
The manuscript is too long. The main subject as declared in title and abstract is comparing the resistivity, mobility and free carrier concentration estimated by electrical and optical methods (Hall effect and ellipsometry). This part of manuscript is new and interesting. The rest of the manuscript is less interesting and part of it could be omitted. In particularly:
The influence of oxygen partial pressure and Al doping, authors already published.
Experimental setup is already described in previously published articles.
The model of measured AZO thin films for fitting the ellipsometry measurements and parametric model containing two Lorentz oscillators in data analysis was described in previous published articles by the same authors.
The deposition method is interesting, but the setup is unique, and parameters devoted to it have limited value (for example H value in Table 1)
Join the all above unnecessary items resulted in incomplete information and lack of proper discussion the results. However, it is on the authors to keep the concept as it is.
What in my opinion should be corrected are items listed below:
Response: For the complete manuscript, we almost have reviewed all our published articles including the experimental data, measurement data, etc.
We added the below “The deposited film belongs to an amorphous film rather than a CTO film when the atomic percentage is greater than 13 at.%.” in manuscript. So, H value has limited value.
Experimental data are missing.
Annealing was done in air?
Response: Annealing was done in air and “in air” was added in the article.
AZO used for annealing was 1.5% Al, but what was PO2?
Response: AZO for Al doping 1.5 at.% in Figures was revised to AZO-1.5, and “PO2” to “PO2”.
Some cumbersome statements should be reformulated or omitted
Response: The deposition and measurement processes of the film was all omitted in Sample Preparation.
“In this comparison, the spring represents the electrostatic force on the electron caused by all the other electrons and nuclei in the solid, and the dissipative force represents the energy loss due to the emission of a photon. This classical model treats the electron as a particle that has mass orbits with a given trajectory and a certain amount of kinetic energy “
I would say that emission of photons is not a “classical “effect. The BM effect is a consequence of Pauli exclusion principle.
Response: The “classical” word was canceled.
The worst part are Figures.
Figure 4c,d the structure of AZO—what is the concentration of Al?
Response: AZO for Al doping 1.5 at.% in Figure 4c,d were revised to AZO-1.5
Figure 5 It is not clear are the data on the axes connected or not. E.g. for example, grain size vs Al concentration—were the samples deposited at same PO2 or each point correspond to different PO2. The same for grain size vs temperature of annealing. If the PO2 is the same for these two sets of dana, Figure 5 should be divided into 3 figures. size vs temp. annealing, size vs. oxygen conc. and size vs. Al concentration. If not, the additional explanation to the graphs should be written.
Response: Figure 5 has been divided into 4 figures.What is the concentration of Al in “AZO films “?
(The value for Al% is given on page 9, while Figures 4,5 are on page 5)
Response: AZO for Al doping 1.5 at.% in figures was revised to AZO-1.5.
Round 2
Reviewer 1 Report
I agree to the improvements brought to the paper.
Reviewer 2 Report
I have no further comments.
