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Sol–gel deposition of Al-doped ZnO thin films: effect of additional zinc supply

  • Original Paper: Functional coatings, thin films and membranes (including deposition techniques)
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Abstract

Al-doped ZnO (AZO) films were deposited by sol–gel method. Precursor solutions for sol–gel method usually contain oxygen sources such as water, ethanol, and acetates. Zinc vacancy acceptors tend to be formed under oxygen-rich growth conditions. In this study, glass substrates with a zinc layer were used to supply zinc to the AZO films during calcination annealing. The diffraction peaks of wurtzite ZnO were observed in XRD patterns, and no diffraction peaks corresponding to zinc metal were observed. The AZO films were transparent in the visible range. The average transmittance (400–800 nm) was above 86%. The electrical properties of the AZO films were improved by using the substrates with a zinc layer. The AZO film deposited on the glass substrate with a 100-nm-thick zinc layer showed a resistivity of 9.4 × 10−4 Ω cm.

Graphical Abstract

(a) Typical samples before and after annealing. (b) Resistivity of the AZO films as a function of the zinc layer thickness on the glass substrates. The AZO film deposited on the glass substrate with a 100-nm-thick zinc layer had a resistivity of 9.4 × 104 Ωcm.

Highlights

  • Low-resistivity Al-doped ZnO (AZO) films were deposited by sol-gel method using glass substrates with a zinc layer.

  • The AZO films after calcination annealing were transparent. The average transmittance (400–800 nm) of the AZO films was above 86%.

  • The AZO film deposited on the glass substrate with a 100-nm-thick zinc layer had a resistivity of 9.4 × 10−4 Ω cm.

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Acknowledgements

The authors would like to thank Ms. Noriko Asaka for her kind support for the SEM and EDS observations.

Author contributions

All authors contributed to the study conception and design. Sample preparation, data collection, and analysis were performed by KA and TK. The first draft of the manuscript was written by KA, and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.

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Authors and Affiliations

  1. Department of Electrical and Mechanical Engineering, Nagoya Institute of Technology, Gokiso, Showa, Nagoya, 466-8555, Japan

    Koji Abe & Tasuku Kubota

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  1. Koji Abe
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  2. Tasuku Kubota
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Correspondence to Koji Abe.

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Abe, K., Kubota, T. Sol–gel deposition of Al-doped ZnO thin films: effect of additional zinc supply. J Sol-Gel Sci Technol 108, 28–34 (2023). https://doi.org/10.1007/s10971-023-06183-x

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  • DOI: https://doi.org/10.1007/s10971-023-06183-x

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