Optical Characterization of H-Free a-Si Layers Grown by rf-Magnetron Sputtering by Inverse Synthesis Using Matlab: Tauc–Lorentz–Urbach Parameterization
Abstract
:1. Introduction
2. Experimental Procedure and Preliminary Structural Analysis
2.1. Preparation of H-Free a-Si Thin-Film Samples by RFMS
2.2. Surface, Structural and Optical Characterizations of the a-Si Films
3. Thin-Film Optics Theory and Model Dielectric Function
3.1. Some Basic Theoretical Considerations
3.2. Spectral Transmittance for a Nonuniform Semiconductor Film onto a Transparent Glass Substrate
3.3. Optical Phase Change: Correcting Integer Numbers and
3.4. Determination of the Optical Constants by Applying the TLUC Dispersion Model
3.5. ‘AdjustTransIS’: Matlab Computational Program for Optical Characterization of Amorphous Semiconductor Films
4. Results and Discussion
4.1. Computation of the Optical Properties by ‘AdjustTransIS’
4.2. Comparison with the Transmission Data Analysis by the Swanepoel Envelope Method
4.3. Wemple–DiDomenico Framework: Insight into Material Porosity
4.4. Bruggeman Effective Medium Approximation: Alternate Void-Volume-Fraction Determination
4.5. Absorption Edge and Dielectric Function of RFMS-a-Si
4.6. Determination of the Band-Gap Energy by Tauc’s Extrapolation Method
5. Summary and Concluding Remarks
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Acknowledgments
Conflicts of Interest
Appendix A
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a-Si Material | RFMS-a-Si (Si#1) | RFMS-a-Si (Si#2) | RFMS-a-Si (Si#3) | RFMS-a-Si (Si#4) | e-a-Si Jellison-Modine | i-a-Si Adichi-Mori |
---|---|---|---|---|---|---|
Data reference | Present work | Present work | Present work | Present work | [29] | [32] |
Wavelength/Energy range (nm/eV) | 400–2500 | 400–2500 | 400–2500 | 400–2500 | 0.8–5.9 | 1.5–5.2 |
Figure-of-merit | 0.421 | 0.565 | 0.445 | 0.446 | N/A | N/A |
) | 1.19 | 1.19 | 1.26 | 1.27 | 1.20 | 1.11 |
Offset, | 1.00 (fixed) | 1.00 (fixed) | 1.00 (fixed) | 1.00 (fixed) | 1.15 | 0.17 |
) | 102 | 95 | 96 | 104 | 122 | 150 |
) | 3.72 | 3.73 | 3.70 | 3.65 | 3.45 | 3.40 |
) | 2.54 | 2.26 | 2.29 | 2.35 | 2.54 | 2.55 |
) | 1.76 | 1.73 | 1.78 | 1.79 | N/A | N/A |
) | 253 | 240 | 245 | 245 | N/A | N/A |
) | 2.19 | 1.28 | 1.2 | 1.3 | N/A | N/A |
) | 770 | 1123 | 730 | 795 | N/A | N/A |
) | 777 | 1112 | 735 | 789 | N/A | N/A |
) | 25 | 0 | 12 | 13 | N/A | N/A |
3.2 | 0 | 1.6 | 1.6 | N/A | N/A | |
) | 1.38 | 1.37 | 1.43 | 1.43 | N/A | N/A |
(cm | 591 | 557 | 574 | 604 | N/A | N/A |
Dispersion model | TLUC | TLUC | TLUC | TLUC | TL | TL |
Sample ID | Approach | () | () | () | ||||
---|---|---|---|---|---|---|---|---|
Si#1 | Inverse Synthesis | 18.6 | 3.71 | 3.24 | 29.2 | 3.158 | 20.6 | 20.8 |
Si#1 | Envelope Method | N/A | N/A | 3.26 | 28.0 | 3.099 | 21.2 | 21.4 |
Si#2 | Inverse Synthesis | 19.5 | 3.72 | 3.27 | 28.2 | 3.102 | 22.5 | 22.5 |
Si#2 | Envelope Method | N/A | N/A | 3.33 | 29.1 | 3.199 | 18.4 | 20.8 |
e-a-Si Palik [35] | Reflectance | 20.8 | 3.50 | 3.01 | 30.9 | 3.359 | 15.1 | 13.2 |
i-a-Si Adachi-Mori [32] | VASE | 26.6 | 3.45 | 2.87 | 36.4 | 3.697 | 0 | 0 |
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Márquez, E.; Ruíz-Pérez, J.J.; Ballester, M.; Márquez, A.P.; Blanco, E.; Minkov, D.; Ruano, S.M.F.; Saugar, E. Optical Characterization of H-Free a-Si Layers Grown by rf-Magnetron Sputtering by Inverse Synthesis Using Matlab: Tauc–Lorentz–Urbach Parameterization. Coatings 2021, 11, 1324. https://doi.org/10.3390/coatings11111324
Márquez E, Ruíz-Pérez JJ, Ballester M, Márquez AP, Blanco E, Minkov D, Ruano SMF, Saugar E. Optical Characterization of H-Free a-Si Layers Grown by rf-Magnetron Sputtering by Inverse Synthesis Using Matlab: Tauc–Lorentz–Urbach Parameterization. Coatings. 2021; 11(11):1324. https://doi.org/10.3390/coatings11111324
Chicago/Turabian StyleMárquez, Emilio, Juan J. Ruíz-Pérez, Manuel Ballester, Almudena P. Márquez, Eduardo Blanco, Dorian Minkov, Susana M. Fernández Ruano, and Elias Saugar. 2021. "Optical Characterization of H-Free a-Si Layers Grown by rf-Magnetron Sputtering by Inverse Synthesis Using Matlab: Tauc–Lorentz–Urbach Parameterization" Coatings 11, no. 11: 1324. https://doi.org/10.3390/coatings11111324
APA StyleMárquez, E., Ruíz-Pérez, J. J., Ballester, M., Márquez, A. P., Blanco, E., Minkov, D., Ruano, S. M. F., & Saugar, E. (2021). Optical Characterization of H-Free a-Si Layers Grown by rf-Magnetron Sputtering by Inverse Synthesis Using Matlab: Tauc–Lorentz–Urbach Parameterization. Coatings, 11(11), 1324. https://doi.org/10.3390/coatings11111324