Photonic Characterisation of Indium Tin Oxide as a Function of Deposition Conditions
Indium tin oxide (ITO) has recently gained prominence as a photonic nanomaterial, for example, in modulators, tuneable metasurfaces and for epsilon-near-zero (ENZ) photonics. The optical properties of ITO are typically described by the Drude model and are strongly dependent on the deposition conditi...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-06-01
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| Series: | Nanomaterials |
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| Online Access: | https://www.mdpi.com/2079-4991/13/13/1990 |
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| author | Samuel F. J. Blair Joshua S. Male Stuart A. Cavill Christopher P. Reardon Thomas F. Krauss |
| author_facet | Samuel F. J. Blair Joshua S. Male Stuart A. Cavill Christopher P. Reardon Thomas F. Krauss |
| author_sort | Samuel F. J. Blair |
| collection | DOAJ |
| description | Indium tin oxide (ITO) has recently gained prominence as a photonic nanomaterial, for example, in modulators, tuneable metasurfaces and for epsilon-near-zero (ENZ) photonics. The optical properties of ITO are typically described by the Drude model and are strongly dependent on the deposition conditions. In the current literature, studies often make several assumptions to connect the optically measured material parameters to the electrical properties of ITO, which are not always clear, nor do they necessarily apply. Here, we present a comprehensive study of the structural, electrical, and optical properties of ITO and showed how they relate to the deposition conditions. We use guided mode resonances to determine the dispersion curves of the deposited material and relate these to structural and electrical measurements to extract all relevant material parameters. We demonstrate how the carrier density, mobility, plasma frequency, electron effective mass, and collision frequency vary as a function of deposition conditions, and that the high-frequency permittivity (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi mathvariant="sans-serif">ϵ</mi><mo>∞</mo></msub></semantics></math></inline-formula>) can vary significantly from the value of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi mathvariant="sans-serif">ϵ</mi><mo>∞</mo></msub></semantics></math></inline-formula> = 3.9 that many papers simply assume to be a constant. The depth of analysis we demonstrate allows the findings to be easily extrapolated to the photonic characterisation of other transparent conducting oxides (TCOs), whilst providing a much-needed reference for the research area. |
| first_indexed | 2024-03-11T01:32:56Z |
| format | Article |
| id | doaj.art-1886f2c11119424182285701d31c2ab2 |
| institution | Directory Open Access Journal |
| issn | 2079-4991 |
| language | English |
| last_indexed | 2024-03-11T01:32:56Z |
| publishDate | 2023-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Nanomaterials |
| spelling | doaj.art-1886f2c11119424182285701d31c2ab22023-11-18T17:12:20ZengMDPI AGNanomaterials2079-49912023-06-011313199010.3390/nano13131990Photonic Characterisation of Indium Tin Oxide as a Function of Deposition ConditionsSamuel F. J. Blair0Joshua S. Male1Stuart A. Cavill2Christopher P. Reardon3Thomas F. Krauss4School of Physics, Engineering and Technology, University of York, York, YO10 5DD, UKSchool of Physics, Engineering and Technology, University of York, York, YO10 5DD, UKSchool of Physics, Engineering and Technology, University of York, York, YO10 5DD, UKSchool of Physics, Engineering and Technology, University of York, York, YO10 5DD, UKSchool of Physics, Engineering and Technology, University of York, York, YO10 5DD, UKIndium tin oxide (ITO) has recently gained prominence as a photonic nanomaterial, for example, in modulators, tuneable metasurfaces and for epsilon-near-zero (ENZ) photonics. The optical properties of ITO are typically described by the Drude model and are strongly dependent on the deposition conditions. In the current literature, studies often make several assumptions to connect the optically measured material parameters to the electrical properties of ITO, which are not always clear, nor do they necessarily apply. Here, we present a comprehensive study of the structural, electrical, and optical properties of ITO and showed how they relate to the deposition conditions. We use guided mode resonances to determine the dispersion curves of the deposited material and relate these to structural and electrical measurements to extract all relevant material parameters. We demonstrate how the carrier density, mobility, plasma frequency, electron effective mass, and collision frequency vary as a function of deposition conditions, and that the high-frequency permittivity (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi mathvariant="sans-serif">ϵ</mi><mo>∞</mo></msub></semantics></math></inline-formula>) can vary significantly from the value of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi mathvariant="sans-serif">ϵ</mi><mo>∞</mo></msub></semantics></math></inline-formula> = 3.9 that many papers simply assume to be a constant. The depth of analysis we demonstrate allows the findings to be easily extrapolated to the photonic characterisation of other transparent conducting oxides (TCOs), whilst providing a much-needed reference for the research area.https://www.mdpi.com/2079-4991/13/13/1990indium tin oxideDrude modelguided mode resonanceepsilon-near-zero materialtransparent conducting oxidesnanomaterial |
| spellingShingle | Samuel F. J. Blair Joshua S. Male Stuart A. Cavill Christopher P. Reardon Thomas F. Krauss Photonic Characterisation of Indium Tin Oxide as a Function of Deposition Conditions Nanomaterials indium tin oxide Drude model guided mode resonance epsilon-near-zero material transparent conducting oxides nanomaterial |
| title | Photonic Characterisation of Indium Tin Oxide as a Function of Deposition Conditions |
| title_full | Photonic Characterisation of Indium Tin Oxide as a Function of Deposition Conditions |
| title_fullStr | Photonic Characterisation of Indium Tin Oxide as a Function of Deposition Conditions |
| title_full_unstemmed | Photonic Characterisation of Indium Tin Oxide as a Function of Deposition Conditions |
| title_short | Photonic Characterisation of Indium Tin Oxide as a Function of Deposition Conditions |
| title_sort | photonic characterisation of indium tin oxide as a function of deposition conditions |
| topic | indium tin oxide Drude model guided mode resonance epsilon-near-zero material transparent conducting oxides nanomaterial |
| url | https://www.mdpi.com/2079-4991/13/13/1990 |
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