Nanostructure of Al-ZnO Thin Films on ITO/Glass Substrate Prepared via Sol-Gel Spin Coating Process

Abstract:

Solar energy is probably the most important source of renewable energy available today. ZnO is a potential material for the fabrication solar cell. Zinc oxide (ZnO) nano-structure semiconductors have been recently gained much attention in the electronic and optical device applications. ZnO is a compound semiconductor, which has a high extention band gap (E= 3.37 eV) at room temperature (RT) with a Wurtzite crystal structure. In particular ZnO can be employed as the transparent conducting oxide (TCO) in solar cell applications due to its high productivity, non-toxic, low cost, and excellent electrical conductivity. In this study, aluminum doped ZnO (AZO) polycrystalline films have been fabricated on ITO/substrates via a sol-gel spin-coating method. The quantity of aluminum doping in the solution was 4.0 %. After synthesis, the films were pre-heated at 300°C for 25 min and after that the films were inserted in a Tub-furnace and post-annealing at 450°C to 750°C for 1 h. The microstructural and structural properties of AZO films were studied through X-ray diffraction (XRD), UV-Vis NIR and scanning electron microscope (SEM) analysis. The TCO applications of the transmittance of samples were also examined. The results showed that the annealing temperature does not seriously affect on the transmittance of AZO films over the visible range.

• Periodical: Solid State Phenomena (Volume 268)
• Pages: 279-283
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.268.279
• Online since: October 2017
• Authors: HASSAN NOORIKALKENARI*, Karim bin Deraman
• Keywords: ITO Glass Substrate, Solar Energy, Sol-Gel, Transparent Conducting Oxide (TCO), Zinc Oxide

References

[1] T.H. Han, Y. Lee, M.R. Choi, S. Woo, S. Bae, B.H. Hong, J.H. Ahn, T.W. Lee, Extremely efficient flexible organic light-emitting diodes with modified graphene anode, Nature Photonics, 16 (2012) 105-10.

DOI: 10.1038/nphoton.2011.318

[2] B.S. Ong, C. Li, Y. Li, Y. Wu, R. Loutfy, Stable, solution-processed, high-mobility ZnO thin-film transistors, Journal of the American Chemical Society. 129 (2007) 2750-1.

DOI: 10.1021/ja068876e

[3] A. Kim, Y. Won, K. Woo, C. Kim, J. Moon, Highly transparent low resistance ZnO/Ag nanowire/ZnO composite electrode for thin film solar cells, ACS nano. 7 (2013) 1081-91.

DOI: 10.1021/nn305491x

[4] X. W. Sun, J. Z. Huang, J. X. Wang, Z. Xu, A ZnO nanorod inorganic/organic heterostructure light-emitting diode emitting at 342 nm, Nano Letters. 123 (2012)1219-23.

DOI: 10.1021/nl080340z

[5] E. D. Gaspera, M. Bersani, M. Cittadini, M. Guglielmi, D. Pagani, R. Noriega, S. Mehra, A. Salleo, A. Martucci, Low-temperature processed Ga-doped ZnO coatings from colloidal inks, Journal of the American Chemical Society. 135(2013)3439-48.

DOI: 10.1021/ja307960z

[6] W. J. Jeong, S. K. Kim, G. C. Park, Preparation and characteristic of ZnO thin film with high and low resistivity for an application of solar cell, Thin Solid Films. 506 (2006)180-3.

DOI: 10.1016/j.tsf.2005.08.213

[7] S. Ishibashi, Y. Higuchi, Y. Ota, K. Nakamura, Low resistivity indium–tin oxide transparent conductive films. Effect of introducing H2O gas or H2 gas during direct current magnetron sputtering, Journal of Vacuum Science & Technology A. 8 (1990).

DOI: 10.1016/0042-207x(91)90990-z

[8] P. L. Tat, K. Deraman, R. Hussin, W. Shamsuri, W. Nurulhuda, Z. Ibrahim, The Structural and Surface Morphology of Annealed ZnO Films, InAdvanced Materials Research. 903 (2014) 73-77.

DOI: 10.4028/www.scientific.net/amr.903.73

[9] H. Noorik, K. B. Deraman, ZnO nanostructure: A review on their growth and structural properties by thermal evaporate and Chemical Vapor Deposition methods.

[10] C. Li, M. Furuta, T. Matsuda, T. Hiramatsu, H. Furuta, T. Hira, Effects of substrate on the structural, electrical and optical properties of Al-doped ZnO films prepared by radio frequency magnetron sputtering, Thin Solid Films. 517 (2009) 3265-8.

DOI: 10.1016/j.tsf.2008.11.103

[11] H. S. Kang, J. S. Kang, S. S. Pang, E. S. Shim, S. Y. Lee, Variation of light emitting properties of ZnO thin films depending on post-annealing temperature, Materials Science and Engineering: B. 120 (2003) 313-6.

DOI: 10.1016/s0921-5107(02)00730-4

[12] S. W. Kuo, W. C. Chen, F. I. Lai, C. P. Cheng, H. C. Kuo, S. C. Wang, W. F. Hsieh, Effects of doping concentration and annealing temperature on properties of highly-oriented Al-doped ZnO films, Journal of crystal growth. 287(2006) 78-84.

DOI: 10.1016/j.jcrysgro.2005.10.047

[13] S. S. Kumar, P. Venkateswarlu, V. R. Rao, G. N. Rao, Synthesis, characterization and optical properties of zinc oxide nanoparticles, International Nano Letters. 3 (2013)1-6.

DOI: 10.1186/2228-5326-3-30

[14] J. H. Lee, K. H. Ko, B. O. Park, Electrical and optical properties of ZnO transparent conducting films by the sol–gel method, Journal of Crystal Growth. 247 (2003) 119-25.

DOI: 10.1016/s0022-0248(02)01907-3

[15] K. E. Lee, M. Wang, E. J. Kim, S. H. Hahn, Structural, electrical and optical properties of sol–gel AZO thin films, Current Applied Physics. 9 (2009)683-7.

DOI: 10.1016/j.cap.2008.06.006