Effects of content and thickness on the microstructure as well as optical and electrical properties of oxidized Al-doped ZnO Films

Document Type : Article

Authors

1 a. Key Laboratory of Electromagnetic Processing of Materials (Ministry of Education), Northeastern University, Shenyang 110819, China. b. School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China

2 a. Key Laboratory of Electromagnetic Processing of Materials (Ministry of Education), Northeastern University, Shenyang 110819, China. c. School of Metallurgy, Northeastern University, Shenyang 110819, China.

3 a. Key Laboratory of Electromagnetic Processing of Materials (Ministry of Education), Northeastern University, Shenyang 110819, China. b. School of Materials Science and Engineering, Northeastern University, Shenyang 110819, China.

Abstract

It is crucial to control conductivity and optical transmittance of Al doped ZnO (AZO) thin films in application of optoelectronic materials. In this paper, AZO thin films are prepared by oxidizing thermal evaporated Zn-Al thin films in open air. Then, the effects of Al contents and film thicknesses on microstructure, optical and electrical properties of the AZO films are studied. The results show that the optical and electrical properties of the AZO films are affected by the Al content and thickness changing. The Haacke figure of merit reaches 2.91×10-4 Ω-1. The film surface morphology is changed by the Al content. Nanowire is formed when the Al content is 9.58%. The Al2O3 phase appears with an excessive Al content. The transmittance of the AZO films is less than 25% when the Al content is more than 9.58%. The grain size first increases and then decreases with the increase of film thickness when the Al contents remain at 2%. Within the limits of available transmittance, the sheet resistance and transmittance of the AZO thin film decrease exponentially with the film thickness increasing.

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References

References:
1. Nomura, K., Ohta, H., Ueda, K., Kamiya, T., Hirano, M., and Hosono, H. "Thin-film transistor fabricated in single-crystalline transparent oxide semiconductor", Science, 300, pp. 1269-1272 (2003).
2. Maryama, H. and Abbassi, A. "Comparative study of accurate experimentally determined and calculated band gap of amorphous ZnO layers", Mater. Lett., 166, pp. 206-209 (2016).
3. Ozgur, U., Alivov, Y.I., Liu, C., Teke, A., Reshchikov, M.A., Dogan, S., Avrutin, V., Cho, S.J., and Morkoc, H. "A comprehensive review of ZnO materials and devices", J. Appl. Phys., 98, pp. 11-1 (2005).
4. Purohit, A., Chander, S., Sharma, A., Nehra, S.P., and Dhaka, M.S. "Impact of low temperature annealing on structural, optical, electrical and morphological properties of ZnO thin films grown by RF sputtering for photovoltaic applications", Opt. Mater., 49, pp. 51-58 (2015).
5. Fang, G., Li, D., and Yao, B.L. "Fabrication and vacuum annealing of transparent conductive AZO thin films prepared by DC magnetron sputtering", Vacuum., 68, pp. 363-372 (2002).
6. Ravichandran, K., Begum, N.J., Swaminathan, K., and Sakthivel, B. "Fabrication of a double layered FTO/AZO film structure having enhanced thermal, electrical and optical properties, as a substitute for ITO films", Superlattices Microstruct., 64, pp. 185- 195 (2013).
7. Yan, X., Li, W., Aberle, A.G., and Venkataraj, S. "Textured AZO for Thin-Film Si Solar Cells: Towards understanding the effect of AZO film thickness on the surface texturing properties", Procedia Engineering, 139, pp. 134-139 (2016).
8. Boujnah, M., Boumadyan, M., Naji, S., Benyoussef, A., Kenz, A.E., and Loulidi, M. "High efficiency of transmittance and electrical conductivity of V doped ZnO used in solar cells applications", J. Alloy. Compd., 671, pp. 560-565 (2016).
9. Suzuki, T. and Isoda, M. "Translucent material and method for manufacturing the same", CN 101006026 A (2007).
10. Rezaie, M.N., Manavizadeh, N., Abadi, E.M.N., Nadimi, E., and Boroumand, F.A. "Comparison study of transparent RF-sputtered ITO/AZO and ITO/ZnO bilayers for near UV-OLED applications", Appl. Surf. Sci., 392, pp. 549-556 (2017).
11. Lord, A.M., Maffeis, T.G., Allen, M.W., Morgan, D., Davies, P.R., Jones, D.R., Evansb, J.E., Smithe, N.A., and Wilkse, S.P. "Surface state modulation through wet chemical treatment as a route to controlling the electrical properties of ZnO nanowire arrays investigated with XPS", Appl. Surf. Sci., 320, pp. 664-669 (2014).
12. Chakraborty, M., Mahapatra, P., and Thangavel, R. "Structural, optical and electrochemical properties of Al and Cu co-doped ZnO nanorods synthesized by a hydrothermal method", Thin Solid Films, 612, pp. 49- 54 (2016).
13. Hao, X., Ma, J., Zhang, D., Yang, T., Ma, H., Yang, Y., and Huang, J. "Thickness dependence of structural, optical and electrical properties of ZnO:Al films prepared on flexible substrates", Appl. Surf. Sci., 189, pp. 137-142 (2002).
14. Zhang, L., Huang, J., Yang, J., Tang, K., Ren, B., Hu, Y., Wang, L., and Wang, L. "The effects of thickness on properties of B and Ga co-doped ZnO films grown by magnetron sputtering", Mater. Sci. Semicond. Process, 42, pp. 277-282 (2016).
15. Liu, Y., Yang, S., Wei, G., Song, H., Cheng, C., Xue, C., and Yuan, Y. "Electrical and optical properties dependence on evolution of roughness and thickness of Ga:ZnO films on rough quartz substrates", Surf. Coat. Technol., 205, pp. 3530-3534 (2011).
16. Wang, Y., Lu, J., Bie, X., Gong, L., Li, X., Song, D., Zhao, X., Ye, W., and Ye, Z. "Transparent conductive Al-doped ZnO thin films grown at room temperature", J. Vac. Sci. Technol. A, 29, pp. 031505 (2011).
17. Lee, H.W., Lau, S.P., Wang, Y.G., Tse, K.Y., Hng, H.H., and Tay, B.K. "Structural, electrical and optical properties of Al-doped ZnO thin films prepared by filtered cathodic vacuum arc technique", J. Cryst. Growth, 268, pp. 596-601 (2004).
18. Liang, P., Cai, H., Yang, X., Li, H., Zhang, W., Xu, N., Li, H., Sun, J., and Wu, J.D. "Spectroscopic characterization of the plasmas formed during the deposition of ZnO and Al-doped ZnO films by plasmaassisted pulsed laser deposition", Spectroc. Acta Pt. BAtom. Spectr., 125, pp. 18-24 (2016).
19. Suchea, M., Christoulakis, S., Katsarakis, N., Kitsopoulos, T., and Kiriakidis, G. "Comparative study of zinc oxide and aluminum doped zinc oxide transparent thin films grown by direct current magnetron sputtering", Thin Solid Films, 515, pp. 6562-6566 (2007).
20. Fan, L. "The effect of thickness on electrical and  optical properties of AZO films", Journal of Ceramics, 1, pp. 23-26 (2015).
21. Zhou, H.M., Yi, D.Q., Yu, Z.M., Xiao, L.R., Li, J., and Wang, B. "Microstructure, optical and electrical properties of ZnO:Al prepared by sol-gel method", Acta Metall. Sin., 5, pp. 505-510 (2006).
22. Baskakov, I.V., Legname, G., Gryczynski, Z., and Prusiner, S.B. "Effect of the tungsten oxidation states in the thermal coloration and bleaching of amorphous WO3 films", Thin Solid Films, 384, pp. 298-306 (2001).
23. Li, G., Wang, Z., Wang, Q., Wang, H., Du, J., Ma, Y., and He, J. "Effect of oxidation time under high magnetic field on the microstructure and optical properties of oxidized Co-doped ZnO films", Acta Metall. Sin., 12, pp. 1538-1542 (2014).
24. Yang, J., Wang, C., Tao, K., and Fan, Y. "A new method to obtain Cu films with lower resistivity and higher interface adhesion on different substrates", J. Vac. Sci. Technol., 13, pp. 481-484 (1995).
25. Haacke, G. "New figure of merit for transparent conductors", J. Appl. Phys., 47, pp. 4086-4089 (1976).
26. Wang, Q., Cao, Y., Li, G., Wang, K., Du, J., and He, J. "Improving the magnetic properties of molecularbeam- vapor-deposited Ni45Fe55 nanocrystalline films by in-situ high magnetic field application", Sci. Adv. Mater., 5, pp. 447-452 (2013).
27. Al-Ghamdi, A.A., Alhumminay, H., Abdel-Wahab, M.S., and Yahia, I.S. "Structure, optical constants and non-linear properties of high quality AZO nano-scale thin films", Optik, 127, pp. 4324-4328 (2016).
28. Zhang, X., Chen, Y., Zhang, S., and Qiu, C. "High photocatalytic performance of high concentration Aldoped ZnO nanoparticles", Sep. Purif. Technol., 172, pp. 236-241 (2017).
29. Bahramian, R., Eshghi, H., and Moshaii, A. "Influence of annealing temperature on morphological, optical and UV detection properties of ZnO nanowires grown by chemical bath deposition", Mater. Des., 107, pp. 269-276 (2016).
30. Lin, Y.C., Jian, Y.C., and Jiang, J.H. "A study on the wet etching behavior of AZO (ZnO:Al) transparent conducting film", Appl. Surf. Sci., 254, pp. 2671-2677 (2008).
31. Zhong, Y., Ping, D., Song, X., and Yin, F. "Determination of grain size by XRD profile analysis and TEM counting in nano-structured Cu", J. Alloy. Compd., 476, pp. 113-117 (2009).
Scientia Iranica
Volume 27, Issue 3
Transactions on Civil Engineering (A)
May and June 2020
Pages 1019-1027

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