Influence of Annealing Atmosphere on Microstructure and Optical Properties of ZnO Thin Films

Abstract:

In this work, the ZnO films are deposited on conducting silicon chips by radio frequency magnetron sputtering. The as-deposited thin films are annealed at 800 °C in a N₂, O₂ and CO+N₂ atmosphere for 1h, respectively. The microstructure and electrical properties of the films are comprehensively investigated. XRD studies reveal that the ZnO films have a hexagonal wurtzite structure and they are highly oriented along (002) direction. The surface roughness of ZnO films decreased after annealing, which indicates better film quality. Room temperature PL spectrum is used to investigate the band gap and native defects existing in the films. Defects of thin films for different annealing conditions are analyzed in detail and the possible mechanism of the defects emission is discussed. We suggest that annealing atmosphere of CO+N₂ is the most suitable annealing conditions for obtaining ZnO thin films with better crystal quality and good luminescence performance.

• Periodical: Solid State Phenomena (Volume 281)
• Pages: 673-678
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.281.673
• Online since: August 2018
• Authors: Jing Shang*, Liao Ying Zheng, Xue Shi, Jiang Tao Zeng, Guo Rong Li
• Keywords: Annealing Atmosphere, Optical Properties, ZnO Thin Films

References

[1] Y.W. Heo, L.C. Tien, D.P. Norton, S.J. Pearton, B.S. Kang, F. Ren, J.R. LaRoche, Pt/ZnO nanowire Schottky diodes, Applied Physics Letters, 85 (2004) 3107-3109.

DOI: 10.1063/1.1802372

[2] B.B. Rao, Zinc oxide ceramic semi-conductor gas sensor for ethanol vapour, Materials Chemistry and Physics, 64 (2000) 62-65.

DOI: 10.1016/s0254-0584(99)00267-9

[3] G.-x. Wang, N. Li, H.-l. Hu, Y.-c. Yu, Process of direct copper plating on ABS plastics, Appl Surf Sci, 253 (2006) 480-484.

[4] A. Ortiz, C. Falcony, J. Hernandez, M. Garcia, J.C. Alonso, Photoluminescent characteristics of lithium-doped zinc oxide films deposited by spray pyrolysis, Thin Solid Films, 293 (1997) 103-107.

DOI: 10.1016/s0040-6090(96)09114-6

[5] Y.S. Kim, W.P. Tai, S.J. Shu, Effect of preheating temperature on structural and optical properties of ZnO thin films by sol-gel process, Thin Solid Films, 491 (2005) 153-160.

DOI: 10.1016/j.tsf.2005.06.013

[6] T. Tian, L. Cheng, L. Zheng, J. Xing, H. Gu, S. Bernik, H. Zeng, W. Ruan, K. Zhao, G. Li, Defect engineering for a markedly increased electrical conductivity and power factor in doped ZnO ceramic, Acta Mater., 119 (2016) 136-144.

DOI: 10.1016/j.actamat.2016.08.026

[7] A.N. Gruzintsev, E.E. Yakimov, Annealing effect on the luminescent properties and native defects of ZnO, Inorganic Materials, 41 (2005) 725-729.

DOI: 10.1007/s10789-005-0199-5

[8] X. Gu, S. Sabuktagin, A. Teke, D. Johnstone, H. Morkoc, B. Nemeth, J. Nause, Effect of thermal treatment on ZnO substrate for epitaxial growth, J Mater Sci-Mater El, 15 (2004) 373-378.

DOI: 10.1023/b:jmse.0000025681.89561.13

[9] A.C. Rastogi, S.B. Desu, P. Bhattacharya, R.S. Katiyar, Effect of strain gradation on luminescence and electronic properties of pulsed laser deposited zinc oxide thin films, Journal of Electroceramics, 13 (2004) 345-352.

DOI: 10.1007/s10832-004-5124-9

[10] X. Li, Y. Wang, W. Liu, G. Jiang, C. Zhu, Study of oxygen vacancies' influence on the lattice parameter in ZnO thin film, Materials Letters, 85 (2012) 25-28.

DOI: 10.1016/j.matlet.2012.06.107

[11] J.P. Zheng, H.S. Kwok, Preparation of indium tin oxide-films at room tempertature by plused-laster deposition, Thin Solid Films, 232 (1993) 99-104.

DOI: 10.1016/0040-6090(93)90769-l

[12] A. Kaschner, U. Haboeck, M. Strassburg, M. Strassburg, G. Kaczmarczyk, A. Hoffmann, C. Thomsen, A. Zeuner, H.R. Alves, D.M. Hofmann, B.K. Meyer, Nitrogen-related local vibrational modes in ZnO : N, Applied Physics Letters, 80 (2002) 1909-(1911).

DOI: 10.1063/1.1461903

[13] C.L. Du, Z.B. Gu, M.H. Lu, J. Wang, S.T. Zhang, J. Zhao, G.X. Cheng, H. Heng, Y.F. Chen, Raman spectroscopy of (Mn, Co)-codoped ZnO films, Journal of Applied Physics, 99 (2006).

DOI: 10.1063/1.2208298

[14] J. Kennedy, P.P. Murmu, J. Leveneur, A. Markwitz, J. Futter, Controlling preferred orientation and electrical conductivity of zinc oxide thin films by post growth annealing treatment, Appl Surf Sci, 367 (2016) 52-58.

DOI: 10.1016/j.apsusc.2016.01.160

[15] C. Madhu, N. Kaur, I. Kaur, Band gap engineering and photoluminescence studies of imine linked ZnO nanoparticles synthesized by direct precipitation route, Materials Letters, 218 (2018).

DOI: 10.1016/j.matlet.2018.02.039

[16] Y. Sun, J.B. Ketterson, G.K.L. Wong, Excitonic gain and stimulated ultraviolet emission in nanocrystalline zinc-oxide powder, Applied Physics Letters, 77 (2000) 2322-2324.

DOI: 10.1063/1.1316069

[17] P. Zu, Z.K. Tang, G.K.L. Wong, M. Kawasaki, A. Ohtomo, H. Koinuma, Y. Segawa, Ultraviolet spontaneous and stimulated emissions from ZnO microcrystallite thin films at room temperature, Solid State Communications, 103 (1997) 459-463.

DOI: 10.1016/s0038-1098(97)00216-0

[18] F. Oba, M. Choi, A. Togo, I. Tanaka, Point defects in ZnO: an approach from first principles, Science and Technology of Advanced Materials, 12 (2011).

DOI: 10.1088/1468-6996/12/3/034302

[19] I. Satoh, T. Kobayashi, K. Katayama, T. Okada, T. Itoh, Magneto-photoluminescence of novel magnetic semiconductor Zn1-xCrxO grown by PLD method, Applied Physics a-Materials Science & Processing, 79 (2004) 1445-1447.

DOI: 10.1007/s00339-004-2807-7

[20] Y.F. Lu, H.Q. Ni, Z.H. Mai, Z.M. Ren, The effects of thermal annealing on ZnO thin films grown by pulsed laser deposition, Journal of Applied Physics, 88 (2000) 498-502.

DOI: 10.1063/1.373685

[21] B.X. Lin, Z.X. Fu, Y.B. Jia, Green luminescent center in undoped zinc oxide films deposited on silicon substrates, Applied Physics Letters, 79 (2001) 943-945.

DOI: 10.1063/1.1394173