The Optical, Electrical and Surface Differences between As-Deposited and Annealed NiO Films Produced by Ultrasonic Spray Pyrolysis

Öz

The interest in NiO films has been growing fast due to their importance in many applications in science and technology. NiO films are an attractive material and are used common application area such as an antiferromagnetic layer, p-type transparent conducting film, electrochromic devices and chemical sensors. Also, NiO is a good candidate for p-type semiconductor films due to its wide band gap energy from 3.6 to 4.0 eV. In this work, NiO films have been grown on glass substrates by ultrasonic spray pyrolysis technique using NiCl₂.6H₂O as spraying solution. Films have been annealed at 500 °C in air during 1 h. Optical measurements of NiO film have been carried out at room temperature using a UV-VIS spectrophotometer.  Band gap of as-deposited and annealed films have been calculated by using optical method and found as 3.67 eV and 3.7 eV, respectively. Thicknesses of the films have been determined by filmetrics thin film measurement system. Surface properties of the films have been investigated with an atomic force microscope and electrical resistivity measurements have been performed by a four probe set-up. Consequently, the optical, electrical and surface differences have been determined between as-deposited and annealed NiO films produced by ultrasonic spray pyrolysis.

Anahtar Kelimeler

• NiO films, Atomic force microscopy, four-probe method, band gap.

Kaynakça

1. Chopra, K.L., Major, S., Pandya, D.K., (1983). Transparent conductors-A status review. Thin Solid Films, 102(1), 1-46.
2. He, J., Lindström, H., Hagfeldt, A., Lindquist, S.E., (1999). Dye-Sensitized Nanostructured p-Type Nickel Oxide Film as a Photocathode for a Solar Cell.Journal of Physics and Chemistry B, 103, 8940-8943.
3. Boschloo, G., Hagfeldt, A., (2001). Spectroelectrochemistry of Nanostructured NiO. Journal of Physics and Chemistry B, 105, 3039-3044.
4. Lu, Y.M., Hwang, W.S., Yang, J.S., (2002). Effects of substrate temperature on the resistivity of non-stoichiometric sputtered NiOx films. Surface Coating Technology,155, 231-235.
5. Hotovy, I., Huran, J., Spiess, L., Liday, J., Sitter, H., Hascik, S., (2003). The influence of process parameters and annealing temperature on the physical properties of sputtered NiO thin films. Vacuum, 691, 237-242.
6. Bandara, J., Divarathne, C.M., Nanayakkara, S.D., (2004). Corrigendum to ‘‘Fabrication of n–p junction electrodes made of n-type SnO2 and p-type NiO for control of charge recombination in dye-sensitized solar cells. Solar Energy Materials and Solar Cells 81, 429-437.
7. Chan, I.M., Hong, F.C.,(2004). Improved performance of the single-layer and double- layer organic light emitting diodes by nickel oxide coated indium tin oxide anode. Thin Solid Films, 450, 304-311.
8. Penin, N., Rougier, A., Laffont, L., Poizat, P., Tarascon, J.M., (2006). Improved cyclability by tungsten addition in electrochromic NiO thin films. Solar Energy Materials and Solar Cells, 90, 422-433.

9. Kamal, H., Elmaghraby, E.K., Ali, S.A., Abdel-Hady, K., (2005). The electrochromic behavior of nickel oxide films sprayed at different preparative conditions. Thin Solid Films 483, 330-339.
10. Olivier, J., Servet, B., Vergnolle, M., Mosca, M., Garry, G., (2001). Stability/instability of conductivity and work function changes of ITO thin films, UV-irradiated in air or vacuum: Measurements by the four-probe method and by Kelvin force microscopy. Synthetic Met. 122, 87-89.
11. Fujii, E., Tomozawa, A., Torii, H., Takayama, R., (1996). Preferred Orientations of NiO Films Prepared by Plasma-Enhanced Metalorganic Chemical Vapor Deposition. Journal of Applied Physics, 35, L328-330.
12. Sato, H., Minami, T., Takata, S., Yamada, T., (1993). Transparent conducting p-type NiO thin films prepared by magnetron sputtering. Thin Solid Films, 236 27-31.
13. Kitao, M., Izawa, K., Urabe, K., Komatsu, T., (1994).Preparation and Electrochromic Properties of RF-Sputtered NiO Films Prepared in Ar / 02 / H2 Atmosphere. Japan Journal of Applied Physics, 33, 6656-6662.
14. Kumagai, H., Matsumoto, M., Toyoda, K., Obara, M., (1996). Preparation and charactesictics nickel oxide thin film by controlled growth with sequential surface chemical reactions. Journal of Material Science Letters, 15, 1081-1083.
15. Kunz, A.B., (1981). Electronic structure of NiO. Journal of Physics C. 14L, 445.
16. Adler, D., Feinlei, J., (1970). Electrical and Optical Properties of Narrow-Band Materials. Physics Review B. 2, 3112.
17. Dinescu, M., Verardi, P., (1996). ZnO thin film deposition by laser ablation of Zn target in oxygen reactive atmosphere. Applied Surface Science, 106, 149-158.
18. Dakhel, A.A., Ali-Mohamed, A.Y., (2009). Structural, electrical, and optical absorption properties of LaxCd1−xO solid solution films obtained by sol–gel method. Materials Chemistry and Physics, 113, 356-360.
19. Subramanyam T.K., Uthanna S., Sinivasulu Naidu B.,
20. (1998). Preparation and
21. characterization of CdO films deposited by dc magnetron reactive sputtering. Materials
22. Letters, 35, 214-220.
23. Gurumurugan, K., Mangalaraj, D., Narayandass, Sa.K., (1996). Magnetron Sputtered Transparent Conducting CdO Thin Films. Journal of Electronic Materials, 25, 765-770.
24. Gomez, M., Medina, A., Estrada, W. (2000).Improved electrochromic films of NiOx and WOxPy obtained by spray pyrolysis. Solar Energy Materials & Solar Cells, 64, 297-309.
25. Reguig, B.A., Khelil, A., Cattin, L., Morsli, M., Berne`de, J.C. (2007). Properties of NiO thin films deposited by intermittent spray pyrolysis process. Applied Surface Science, 253, 4330–4334.
26. Yoshida, H., Deguchi, H., Kawano, M., Hashino, K., Inagaki, T., Ijichi, H., Horiuchi, M., Kawahara, K., Suda, S. (2007). Study on pyrolysing behavior of NiO–SDC composite particles prepared by spray pyrolysis technique. Solid State Ionics, 178, 399–405.
27. Orel, Z.C. Hutchins, M.G. McMeeking, G. (1993). The electrochromic properties of hydrated nickel oxide films formed by colloidal and anodic deposition. Sol. Energy Mater. Sol. Cell, 30, 327-337.
28. Vazquez Luna, J.G., Zehe, A., Zeleya-Angel, O., (1999). Chemical CdS thin-Şlm deposition influenced by external electric and magnetic Şelds. Crystal Resreach Technology, 34, 949–958.
29. Cattin, L., Reguig, B.A., Khelil, A., Morsli, M., Benchouk, K., J Berne`de, C., (2008). Properties of NiO thin films deposited by chemical spray pyrolysis using different precursor solutions. Applied Surface Science, 254, 5814–5821.
30. Boukhackem, A., Boughalmi, R., Karyaoui, M., Chtourou, R., (2014). Study of substrate temperature effects on stuructural, optical, mechanical and opto-thermal properties of NiO sprayed semiconductor thin films. Material Science and Engineering B, 188, 72-77.
31. Kamal, H., Elmaghraby, E.K., Ali, S.A., Abdel-Hady, K. (2004). Characterization of nickel oxide films deposited at different substrate temperatures using spray pyrolysis. J. Cryst. Growth, 262, 424-434.
32. Pankove, J.I., (1971). Optical Processes in Semiconductors. Prentice-Hall Inc., Englewoord Cliffs, NJ. USA.
33. Urbach, F., (1953).The Long-Wavelength Edge of Photographic Sensitivity and of the Electronic Absorption of Solids. Physics Review, 92, 1318-1324.
34. Li, Q.H., Wan, Q., Liang, Y.X., Wang, T.H. (2004). Electronic transport through individual ZnO nanowires. Appl. Phys. Lett., 84, 4556-4558.
35. Zhu, B.L., Zeng, D.W., Wu, J., Song, W.L., Xie, C.S. (2003). Synthesis and gas sensitivity of In-doped ZnO nanoparticles. J. Mater. Sci. Mater. Electron., 14, 521-526.
36. Zhu, B.L., Xie, C.S., Wu, J., Zeng, D.W., Wang, A.H., Zhao, X.Z., (2006). Influence of Sb, In and Bi dopants on the response of ZnO thick films to VOCs. Mater. Chem. Phys., 96, 459-465.