Hostname: page-component-586b7cd67f-t8hqh Total loading time: 0 Render date: 2024-11-28T09:28:04.224Z Has data issue: false hasContentIssue false

Moisture Resistant Ga-Doped ZnO Films with Highly Transparent Conductivity for Use in Window Layers of Thin-Film Solar Cells

Published online by Cambridge University Press:  21 August 2013

H. -P. Song
Affiliation:
Materials Design Center, Research Institute, Kochi University of Technology, Kami-City, Kochi 782-8502, Japan
H. Makino
Affiliation:
Materials Design Center, Research Institute, Kochi University of Technology, Kami-City, Kochi 782-8502, Japan
S. Kishimoto
Affiliation:
Materials Design Center, Research Institute, Kochi University of Technology, Kami-City, Kochi 782-8502, Japan Department of Mechanical Engineering, Kochi National College of Technology, 200-1 Otsu Monobe Nankoku-City, Kochi 783-8508, Japan
T. Yamamoto
Affiliation:
Materials Design Center, Research Institute, Kochi University of Technology, Kami-City, Kochi 782-8502, Japan
Get access

Abstract

Highly transparent conductive Ga-doped ZnO (GZO) films are one of the promising transparent conductive oxide (TCO) films for use in electrodes of flat display panels and window layers of thin film solar cells. For the ZnO-based TCO films, the stability to damp-heat environment is a crucial issue for practical applications. We will report moisture resistant GZO codoped with indium films (GZO:In) on the basis of analysis of data obtained a damp-heat test for solar cells (85°C and 85% relative humidity for 1000 hours).

We used ZnO sintered targets with contents of 3 wt% Ga2O3 and 0.25 wt% In2O3 to grow GZO:In films in ion plating with direct current arc-discharge system. GZO:In films with different thicknesses (0.1-1 μm) were deposited on glass substrates at 200°C under the O2 flow rate of 15 sccm. As the film thickness increased from 0.1 to 1 μm, the resistivity and sheet resistance decreased from 4.3 μΩm to 2.6 μΩm and from 42.7 Ω/Sq. to 2.6 Ω/Sq., respectively. And the average optical transmittance (Tav) in the range from 0.4 to 1 μm decreased from ∼ 86% to ∼ 75%. The GZO:In film with a thickness of ∼300 nm had a low sheet resistance of 10.5 Ω/Sq. and a Tav of 82.5%. After 1000 hours damp-heat (DH) test under 85°C and 85% relative humidity, the relative change of sheet resistance is 3.4% with a Hall mobility of 26.4 cm2/V.s and a Tav of 82.7% after test. The film thicker than 300 nm has a sheet resistance lower than 10 Ω/Sq. and a relative change of resistance of ∼3% after DH test.

Type
Articles
Copyright
Copyright © Materials Research Society 2013 

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

Minami, T., MRS Bull. 25, 38 (2000).CrossRefGoogle Scholar
Yamamoto, N., Yamada, T., Makino, H. and Yamamoto, T., J. Electrochem. Soc. 157, J13 (2010).CrossRefGoogle Scholar
Minami, T. and Miyata, T., Thin Solid Films 517, 1474 (2008).CrossRefGoogle Scholar
Oh, M., Hwang, D., Seong, D., Hwang, H. and Park, S., Kim, E. D., J. Electrochem. Soc. 155, D599 (2008).CrossRefGoogle Scholar
Ellmer, K., J. Phys. D: Appl. Phys. 34, 3097 (2001).CrossRefGoogle Scholar
Yan, B., Yang, J. and Guha, S., J. Vac. Sci. Technol. A30, 04D108 (2012).CrossRefGoogle Scholar
Pern, F. J., Glick, S. H., Li, X., DeHart, C., Gennett, T., Contreras, M. and Gessert, T. in Stability of TCO window layers for thin-film CIGS solar cells upon damp heat exposures: part III, edited by Dhere, N. G., Wohlgemuth, J. H. and Ton, D. T., (SPIE Proc. 7412, San Diego, CA, 2009) pp. 74120K/1-74120K/12.Google Scholar
Sundaramoorthy, R., Pern, F. J., DeHart, C., Gennett, T., Meng, F. Y., Contreras, M. and Gessert, T. in Stability of TCO window layers for thin-film CIGS solar cells upon damp heat exposures: part II, edited by Dhere, N. G., Wohlgemuth, J. H. and Ton, D. T., (SPIE Proc. 7412, San Diego, CA, 2009) pp. 74120J/1-74120J/12.Google Scholar
Lin, W., Ma, R., Xue, J. and Kang, B., Sol. Energy Mater. Sol. Cells, 91, 1902 (2007).CrossRefGoogle Scholar
Duenow, J. N., Gessert, T. A., Wood, D. M., Egaas, B., Noufi, R. and Coutts, T. J. in Investigation of ZnO: Al Doping Level and Deposition Temperature Effects on CIGS Solar Cell Performance, edited by Durose, K., Gessert, T., Heske, C., Marsillac, S. and Wada, T., (Mater. Res. Soc. Proc. 1012 , San Francisco, CA, 2007) pp. Y01Y08.Google Scholar
Song, H., Makino, H. and Yamamoto, T., submitted to Japanese patent.Google Scholar
Sato, Y., Makino, H., Yamamoto, N. and Yamamoto, T., Thin Solid Films 520, 1395 (2011).CrossRefGoogle Scholar
Yamamoto, T., Song, H. and Makino, H., Phys. Status Solidi C (2013) (in press).Google Scholar
Zhu, H., Hüpkes, J., Bunte, E. and Huang, S.M., Appl. Surf. Sci. 261, 268 (2012).CrossRefGoogle Scholar
Wang, Y., Zhang, X., Bai, L., Huang, Q., Wei, C. and Zhao, Y., Appl. Phys. Lett. 100, 263508 (2012).CrossRefGoogle Scholar