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Theoretical Aspects of Doping of Photovoltaic Materials

Published online by Cambridge University Press:  01 February 2011

H. Katayama-Yoshida*
Affiliation:
Department of Condensed Matter Physics Department of Computational Nanomaterials Design, Nanoscience and Nanotechnology Center, The Institute of Scientific and Industrial Research (ISIR), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan.
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Abstract

The low-resistive p- and n-type transparent conductors are necessary for the efficient photovoltaic (PV) solar cells. We review a new valence control method of co-doping with doping Ga- (or In-, or Alsubstitutional impurity, and Li-interstitial impurity) donor and N-acceptor at the same time for the fabrication of a low-resistive p-type ZnO based upon the ab initio calculation. We compare our materials design to fabricate a low resistive p -type ZnO with the recent successful co-doping experiments. The Delafossite structure of CuAlO2 has great potentiality far p-type transparent conducting oxide to apply the high efficient photovoltaic solar-cells combined with n-type transparent conducting oxides such as ITO (indium tin oxides), SnO2 or ZnO. We have calculated the electronic structure, impurity levels, and formation energy of Cu-vacancy, Al-vacancy, Be, Mg, Ca acceptors at the Al-site, and Be, Mg, Ca donors at the Cu-site. Calculated acceptor energy levels are as follows; Cu-vacancy (-300meV from the VBM [valence band maximum]), Al-vacancy (671 meV from the VBM), Be-acceptor (85 meV from the VBM), Mg-acceptor (200 meV from the VBM), and Ca-acceptor (960 meV from the VBM). We find that the Mg impurity at the Cu-site is more stable than the Al-site. Therefore, Mg impurity acts as donor at the Cu-site in the CuAlO2. This is the reason why Mg doping reduces the p-type conductivity in CuAlO2. We propose the following valence control method for the fabrication of p-type CuAlO2; we should dope the high concentration of Cu-vacancy in order to form the impurity band with reducing the Cu vapor pressure during the PLD or MBE crystal growth method, or we dope the Mg or Be acceptors at the Al-site with reducing the Al vapor pressure and increasing the Cu vapor pressure during the thermal non-equilibrium crystal growth method such as MBE or MOCVD. We compare our materials design with the available experimental data. Finally, we propose the co-doping by 2PS(Se)+InCu+VCu for the fabrication of p-type CuInS2 or CuInSe2 based upon ab initio electronic structure calculation.

Type
Research Article
Copyright
Copyright © Materials Research Society 2003

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References

1. Yamamoto, T. and Katayama-Yoshida, H., Japan. J. Appl. Phys. 36, L180 (1997).Google Scholar
2. Katayama-Yoshida, H. and Yamamoto, T., Phys. Status Solidi b 202, 763 (1997).Google Scholar
3. Katayama-Yoshida, H., Nishimatsu, T., Yamamoto, T. and Orita, N., Phys. Status Solidi B 210, 429 (1998).Google Scholar
4. Katayama-Yoshida, H., Yamamoto, T. and Nishimatsu, T., Compound Semiconductors (Inst. Phys. Conf. Ser. 162, ed Sakaki, H et al (Bristol: IOPP) pp 747756 (1999).Google Scholar
5. Katayama-Yoshida, H., Fabrication method of the low-resistivity p-type AlN Japanese Patent JP H10208612, (1998).Google Scholar
6. Katayama-Yoshida, H., Fabrication method of the low resistivity p-type GaN: Japanese Patent JP H8258054 (1996).Google Scholar
7. Yamamoto, T. and Katayama-Yoshida, H., J. Crystal Growth 214/215, 552 (2000).Google Scholar
8. Yamamoto, T. and Katayama-Yoshida, H., Jpn. J. Appl. Phys. 38, L166–L169 (1999).Google Scholar
9. Katayama-Yoshida, H. and Yamamoto, T., Applied to Japanese Patent (Fabrication method of low-resistivity p-type ZnO: JP H10-287966), and applied to USP and ECP.Google Scholar
10. Joseph, M., Tabata, H., Kawai, T., Jpn. J. Appl. Phys. 38, L1205–L1207 (1999).Google Scholar
11. Look, D. C. and Reynolds, D. C., Litton, C. W., Jones, R. L., Eason, D. B. and Cantwell, G., Appl. Phys. Lett. 81, 1830 (2002).Google Scholar
12. Kawazoe, H., Yasukawa, M., Hyodo, H., Kurita, M., Yanagi, H. and Hosono, H.: Nature 389, 939 (1997).Google Scholar
13. Gong, H., Wang, Y. and Luo, Y.: Appl.Phys.Lett. 76, 3959 (2000).Google Scholar
14. Yanase, A.: Fortran Program for Space Group (Shokabo, Tokyo 1995) 1st ed. [in Japanese].Google Scholar
15. Katayama-Yoshida, H., Koyanagi, T., Funashima, H., Harima, H., and Yanase, A., Solid State Communications. 126, 135 (2003).Google Scholar
16. Stauber, R.E., Parilla, P.A., Perkins, J.D., Ginley, D.S.: Mat. Res. Soc. Symp. Proc. Vol.623, 265 (2000).Google Scholar
17. Yamamoto, T. and Katayama-Yoshida, H., Solar Energy Materials and Solar Cells, 49 (1997) pp. 391397.Google Scholar
18. Zhang, S.B., Wei, S-H., Zunger, A., Katayama-Yoshida, H., Phys. Rev. B57 9642 (1998).Google Scholar
19. Katayama-Yoshida, H., Sato, K. and Yamamoto, T., JSAP International 6, 20 (2002).Google Scholar