Study on the Optical and Gas-Sensing Performance of Zn-doped CuO Films

Abstract

The pure copper oxide thin film was deposited on glass substrates by SILAR method with 30 cycles. To examine the doping effect, Zn-doped films at different doping ratios were prepared under the same conditions as the undoped film. The XRD, SEM and Raman measurements were performed to investigate the morphological and structural properties of the samples. Analysis showed increasing aggregation and amorphous structure with doping. The optical parameters were characterized by spectrophotometer measurement and relevant formulas. The band gap energies were determined to increase from 2.50 to 2.79 eV with the increasing Zn rate. The Hervé and Vandamme, Moss and Ravindra relations were used to determine the refractive index. The room temperature gas-sensing performance for the undoped and doped samples were reported and the responses for 5 ppm gas were calculated as 249 %, 800 %, 189 % and 15 % for the CuO, 1Zn:CuO, 3Zn:CuO and 5Zn:CuO, respectively. The response of CuO thin films changed with doping, and 1% Zn doping rate was determined as the optimal rate in this study.

Keywords

• CuO Thin Films
• Linear Optics
• Gas-Sensing
• Dopant Effect

References

1. Abdel Rafea, M., & Roushdy, N. (2009). Determination of the optical band gap for amorphous and nanocrystalline copper oxide thin films prepared by SILAR technique. Journal of Physics D: Applied Physics, 42, 015413. https://doi.org/10.1088/0022-3727/42/1/015413
2. Balamurugan, B., & Mehta, B. (2001). Optical and structural properties of nanocrystalline copper oxide thin films prepared by activated reactive evaporation. Thin Solid Films, 396(1-2), 90-96. https://doi.org/10.1016/S0040-6090(01)01216-0
3. Çavuşoğlu, H. (2018). Band-gap Control of Nanostructured CuO Thin Films using PEG as a Surfactant. European Journal of Science and Technology, 13, 124-128. https://doi.org/10.31590/ejosat.417941
4. Daoudi, O., Qachaou, Y., Raidou, A., Nouneh, K., Lharch, M., & Fahoume, M. (2019). Study of the physical properties of CuO thin films grown by modified SILAR method for solar cells applications. Superlattices and Microstructures, 127, 93-99. https://doi.org/10.1016/j.spmi.2018.03.006.
5. Das, S., & Alford, T. L. (2013), Structural and optical properties of Ag-doped copper oxide thin films on polyethylene napthalate substrate prepared by low temperature microwave annealing. Journal of Applied Physics, 113, 244905. https://doi.org/10.1063/1.4812584
6. Dhineshbabu, N. R., Rajendran, V., Nithyavathy, N., & Vetumperumal, R. (2016) Study of structural and optical properties of cupric oxide nanoparticles. Applied Nanoscience, 6, 933-939. https://doi.org/10.1007/s13204-015-0499-2
7. Ezenwa, I. (2012). Optical Analysis of Chemical bath Fabricated Cuo Thin Films. Research Journal of Recent Sciences, 1(1), 46-50.
8. Güngör, E. (2019). Zn:CuO Heteroyapıların Yapısal, Optik, Fotolüminesans ve İletim Özellikleri. Nevsehir Journal of Science and Technology, 8(1), 1-13 https://doi.org/10.17100/nevbiltek.509354

9. Hervé, P., & Vandamme, L. K. J. (1994). General relation between refractive index and energy gap in semiconductors. Infrared Physics & Technology, 35(4), 609-615. https://doi.org/10.1016/1350-4495(94)90026-4
10. Huang, Q., Li, J., & Bi, X. (2015). The improvement of hole transport property and optical band gap for amorphous Cu2O films. Journal of Alloys and Compounds, 647, 585-589. https://doi.org/10.1016/j.jallcom.2015.06.147
11. Lu, H.-C., Chu, C.-L., Lai, C.-Y., & Wang, Y.-H. (2009). Property Variations of Direct-Current Reactive Magnetron Sputtered Copper Oxide Thin Films Deposited at Different Oxygen Partial Pressures. Thin Solid Films, 517(15), 4408-4412. https://doi.org/10.1016/j.tsf.2009.02.079
12. Maebana, L. M.., Motsoeneng, R. G., Tshabalala, Z. P., Swart, H. C., Cummings, F. R., Jozela, M., Nkosi, S. S., & Motaung, D. E. (2023). Low-operational temperature for selective detection of xylene gas using a p-n CuO-ZnO heterostructure-based sensor. Journal of Alloys and Compounds, 960, 170683. https://doi.org/10.1016/j.jallcom.2023.170683
13. Mnethu, O., Nkosi, S. S., Kortidis, I., Motaung, D. E., Kroon, R. E., Swart, H. C., Ntsasa, N. G., Tshilongo, J., & Moyo, T. (2020). Ultra-sensitive and selective p-xylene gas sensor at low operating temperature utilizing Zn doped CuO nanoplatelets: Insignificant vestiges of oxygen vacancies. Journal of Colloid and Interface Science, 576, 364-375, https://doi.org/10.1016/j.jcis.2020.05.030
14. Patil, A. S., Patil, M. D., Lohar, G. M., Jadhav, S. T., & Fulari, V. J. (2017). Supercapacitive properties of CuO thin films using modified SILAR method. Ionics, 23, 1259-1266 https://doi.org/10.1007/s11581-016-1921-9
15. Poloju, M., Jayababu, N., & Ramana Reddy, M. V. (2018). Improved gas sensing performance of Al doped ZnO/CuO nanocomposite based ammonia gas sensor. Materials Science and Engineering: B, 227, 61-67. https://doi.org/10.1016/j.mseb.2017.10.012.
16. Tripathy, S. K. (2015). Refractive indices of semiconductors from energy gaps. Optical Materials, 46, 240-246 https://doi.org/10.1016/j.optmat.2015.04.026
17. Yathisha, R. O., & Arthoba, N. Y. (2018). Structural, optical and electrical properties of zinc incorporated copper oxide nanoparticles: doping effect of Zn. Journal of Materials Science, 53, 678-691. https://doi.org/10.1007/s10853-017-1496-5