Hostname: page-component-848d4c4894-4hhp2 Total loading time: 0 Render date: 2024-05-09T19:28:24.187Z Has data issue: false hasContentIssue false
  • English
  • Français

Influence of Annealing Temperature on ZnO Thin Films Prepared by Single and Multi-step Sol-gel Processes

Published online by Cambridge University Press:  01 February 2011

Lee Huat Kelly Koh ,
Shane O'Brien ,
Pierre Lovera ,
Gareth Redmond  and
Gabriel M Crean
Lee Huat Kelly Koh
Affiliation:
kelly.koh@tyndall.ie, Tyndall National Institute, Mesoscale Materials Science, Lee Maltings, Prospect Row, Cork, Ireland
Shane O'Brien
Affiliation:
shane.obrien@tyndall.ie, Tyndall National Institute, Mesoscale Materials Science, Lee Maltings, P rospect Row, Cork, N/A, Ireland
Pierre Lovera
Affiliation:
pierre.lovera@tyndall.ie, Tyndall National Institute, Nanotechnology Dept., Lee Maltings, Prospect Row, Cork, N/A, Ireland
Gareth Redmond
Affiliation:
gareth.redmond@tyndall.ie, Tyndall National Institute, Nanotechnology Dept., Lee Maltings, Prospect Row, Cork, N/A, Ireland
Gabriel M Crean
Affiliation:
gabriel.crean@tyndall.ie, Tyndall National Institute, Mesoscale Materials Science, Lee Maltings, Prospect Row, Cork, N/A, Ireland
Get access

Abstract

ZnO thin films were prepared on borosilicate glass from both single- and multi- step coating deposition of a sol-gel prepared with anhydrous zinc acetate [Zn(C2H3O2)2], monoethanolamine [H2NC2H4OH ] and isopropanol. ZnO films prepared over a range of zinc acetate concentrations, for a fixed annealing temperature, showed that sol-gels prepared with a 0.3M zinc acetate concentration resulted in the formation of films with the greatest degree of c-axis orientation. In this study, a detailed investigation of the influence of process annealing temperature over the range 450 – 550°C on the microstructural, physical, electronic and optical properties of these single and multi-step ZnO thin films around this 0.3M zinc concentration set point is presented. X-ray analysis showed that all single-step deposition thin films were preferentially orientated along the [002] c-axis direction of the crystal. In contrast, only the multi-layer film annealed at 550°C showed similar preferential orientation. All single step deposited films showed a similar average optical transmittance above 87%, independent of annealing temperature. The transmittance of the multi-step films was shown to be strongly correlated to the degree of c-axis orientation. The optical band-gap energy was evaluated to be 3.298 – 3.316 eV for all samples. The photoluminescence spectra of the single layer ZnO films showed a strong emission centred at ca. 405 nm, which blue shifted with increasing annealing temperature. The multi-layer ZnO samples emitted throughout the UV and the visible range, with the samples prepared at 500 and 550°C showing the expected ZnO emission peak at 380 nm. Despite being thicker, the emission from the multi- layer samples was less than measured for the single layer samples. The effect of sol-gel annealing temperature and deposition process on film microstructure, morphology, electrical resistivity and optical transparency is detailed.

Keywords

sol-geloxidethin film
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 957: Symposium K – Zinc Oxide and Related Materials , 2006 , 0957-K10-33
Copyright
Copyright © Materials Research Society 2007

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Pearton, S.J., Abernathy, C.R., Overberg, M.E., Thaler, G.T., Norton, D.P., Theodoropoulou, N., Hebard, A.F., Park, Y.D., Ren, F., Kim, J., Boatner, L. A., J. Appl. Phys. 93(1), 2003, 1.Google Scholar
2. Natsume, Y. and Sakata, H., Thin Solid Films. 372, 2000, 30.Google Scholar
3. Shuler, T. and Aegerter, M.A., Thin Solid Films. 351, 1999, 125.Google Scholar
4. Nunes, P., Costa, D., Fortunato, E. and Martins, R., Vacuum. 64, 2002, 293.Google Scholar
5. Look, D.C., Reynolds, D.C., Litton, C.W., Jones, R.L., Eason, D.B. and Gantwell, G., Appl. Phys. Lett. 81(10), 2002, 1830.Google Scholar
6. Tominaga, K., Takao, T., Fukushima, A., Moriga, T. and Nakabayashi, I., Vacuum. 66, 2002, 505.Google Scholar
7. Naghavi, N., Marcel, C., Dupont, L., Rougier, A., Leriche, J.B. and Guery, C., J. Mater. Chem. 10, 2000, 2315.Google Scholar
8. Krunks, M. and Mellikov, E., Thin Solid Films. 270, 1995, 33.Google Scholar
9. Ohyama, M., Kozuka, H. and Yoko, T., Thin Solid Films, 306, 1997, 78.Google Scholar
10. Lee, J.-H. and Ko, K.-H. and Park, B.-O, J. Crystal Growth. 247, 2003, 119.Google Scholar
11. Li, H., Wang, J., Liu, H. Zhang, H. and Li, X., J. Crystal Growth. 275, 2005, e943.Google Scholar
12. O'Brien, S., Koh, L.H.K. and Crean, G.M., Applied Surface Science 2006-; in pressGoogle Scholar
13. Marotti, R.E., Guerra, D.N., Bello, C., Machado, G. and Dalchiele, E.A., Sol. Energy Mater. Sol. Cells. 82, 2004, 85 Google Scholar
14. Lee, J.-H. and Ko, K.-H. and Park, B.-O, J. Crystal Growth. 247, 2003, 119.Google Scholar
15. Joint Committee on Powder Diffraction Standards, Powder diffraction file, International Center for Diffraction Data, Swarthmore, PA, Card, 1988, 36.Google Scholar
16. Kim, , Tai, W.P. and Shu, S.J., Thin Solid Films, 491, 2005, 153 Google Scholar
17. Lee, J.-H. and Ko, K.-H. and Park, B.-O, J. Crystal Growth. 247, 2003, 119.Google Scholar
18. Sze, S. M., Physics of Semiconductor Devices. Wiley, New York, 1981 Google Scholar
19. Johnson, J. C.; Yan, H.; Yang, P.; Saykally, R. J. J. Phys. Chem. B 2003, 107, 8816 Google Scholar
20. Greene, L. E.; Law, M.; Goldberger, J.; Kim, F.; Johnson, J. C.; Zhang, Y.; Saykally, R. C.; Yang, P. Angew. Chem. Int. Ed. 2003, 42, 3031 Google Scholar