Direct Observation of Carrier Trapping Processes on Fe Impurities in mc-Si Solar Cells

Abstract:

n-situ Mössbauer studies on ⁵⁷Fe solute atoms in Si solar cells are performed: (1) GeV-⁵⁷Mn/⁵⁷Fe implantation into Si solar cells, (2) ⁵⁷Fe diffused n-type Si under light illumination; (3) ⁵⁷Fe diffused solar cells under applying external voltages. The carrier trapping cross sections for the interstitial components with different charge states, Fe_i⁺ and Fe_i²⁺, can be successfully obtained by evaluating the dynamical charge fluctuations within a time scale of 100ns between Fe_i⁺ and Fe_i²⁺ which appear in the Mössbauer spectra of ⁵⁷Fe doped mc-Si solar cells. We further measure the distributions of Fe_i⁺ and Fe_i²⁺ by a Mössbauer Microscope, which we have been developing. The present results provide us a possibility to clarify the carrier trapping process on an atomistic scale directly on the Fe impurities in Si-solar cells.

• Periodical: Solid State Phenomena (Volumes 205-206)
• Pages: 40-46
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.205-206.40
• Online since: October 2013
• Authors: Yutaka Yoshida, Yoshinori Tsukamoto, Masahiro Ichino, Kiyotaka Tanaka
• Keywords: Carrier Trapping Cross Section, Iron Impurities, Mössbauer Spectroscopy, Multicrystalline Si

References

[1] G. Zoth and W. Bergholz, A fast, preparation free method to detect iron in silicon, J. Appl. Phys. 67 (1990) 6764-6771.

DOI: 10.1063/1.345063

[2] Y. Yoshida, Y. Kobayashi, K. Hayakawa, K. Yukihira, A. Yoshida, H. Ueno, F. Shimura and F. Ambe, In situ observation of substitutional and interstitial Fe atoms in Si after GeV-implantation: An in-beam Mössbauer study, Physica B 376-377 (2006).

DOI: 10.1016/j.physb.2005.12.019

[3] Y. Yoshida, S. Horie, K. Niira, K. Fukui and K. Shirasawa, In situ observation of iron atoms in multicrystalline silicon at 1273 and 300 K by Mössbauer spectroscopy, Physica B 376-377 (2006) 227-230.

DOI: 10.1016/j.physb.2005.12.060

[4] Y. Yoshida, S. Aoki, K. Sakata, Y. Suzuki, M. Adachi, and K. Suzuki, Iron impurities in multicrystalline silicon studied by Mössbauer spectroscopy, Physica B 401–402 (2007) 119-122.

DOI: 10.1016/j.physb.2007.08.126

[5] K. Suzuki, Y. Yoshida, K. Hayakawa, K. Yukihira, M. Ichino, and K. Asahi, Observation of iron impurity diffusion in silicon under bending stress by Mössbauer spectroscopy, Hyperfine Interactions 197 (2010) 213-217.

DOI: 10.1007/s10751-010-0218-z

[6] Y. Yoshida, K. Suzuki, Y. Kobayashi, T. Nagatomo, Y. Akiyama, K. Yukihira, K. Hayakawa, H. Ueno, A. Yoshimi, D. Nagae, K. Asahi and G. Langouche, 57Fe charge states in MC-Si solar cells under light illumination after GeV-implantation of 57Mn Hyperfine Interactions 204 (2012).

DOI: 10.1007/s10751-011-0424-3

[7] Y. Yoshida, K. Suzuki, K. Hayakawa, K. Yukihira and H. Soejima, Mössbauer spectroscopic microscope, Hyperfine Interactions 188 (2009) 121-126.

DOI: 10.1007/s10751-008-9897-0

[8] K. Hayakawa, Y. Tsukamoto, Y. Akiyama, M. Kurata, K. Yukihira, H. Soejima, and Y. Yoshida, Development of system and technology for Mössbauer spectroscopic microscope Hyperfine Interactions 206 (2012) 79-82.

DOI: 10.1007/s10751-011-0407-4

[9] K. Tanaka, Y. Akiyama, K. Hayakawa, K. Yukihira, Y. Yoshida, Mapping analyses of Fe-diffused mc-Si using Mössbauer microscope and photoluminescence, Hyperfine Interactions 206 (2012) 75-78.

DOI: 10.1007/s10751-011-0450-1

[10] S. K. Estreicher, M. Sanati, N. Gonzalez Szwacki, Iron in silicon: Interactions with radiation defects, carbon, and oxygen, Phys. Rev. B 77 (2008) 125214-125222.

DOI: 10.1103/physrevb.77.125214

[11] S. Dattagupta, Time-dependent effects and relaxation in Mössbauer Spectroscopy, in: D. P. E. Dickson and F. Berry (Eds. ), Mössbauer Spectroscopy, Cambridge University Press, London, 1986, pp.198-218.

DOI: 10.1017/cbo9780511524233.006