Memorias de investigación
Research Publications in journals:
Precipitated iron: A limit on gettering efficacy in multicrystalline silicon
Year:2013
Research Areas
  • Electric engineers, electronic and automatic (eil),
  • Electronic devices,
  • Materials for electric engineering and electronics
Information
Abstract
A phosphorus diffusion gettering model is used to examine the efficacy of a standard gettering process on interstitial and precipitated iron in multicrystalline silicon. The model predicts a large concentration of precipitated iron remaining after standard gettering for most as-grown iron distributions. Although changes in the precipitated iron distribution are predicted to be small, the simulated post-processing interstitial iron concentration is predicted to depend strongly on the as-grown distribution of precipitates, indicating that precipitates must be considered as internal sources of contamination during processing. To inform and validate the model, the iron distributions before and after a standard phosphorus diffusion step are studied in samples from the bottom, middle, and top of an intentionally Fe-contaminated laboratory ingot. A census of iron-silicide precipitates taken by synchrotron-based X-ray fluorescence microscopy confirms the presence of a high density of iron-silicide precipitates both before and after phosphorus diffusion. A comparable precipitated iron distribution was measured in a sister wafer after hydrogenation during a firing step. The similar distributions of precipitated iron seen after each step in the solar cell process confirm that the effect of standard gettering on precipitated iron is strongly limited as predicted by simulation. Good agreement between the experimental and simulated data supports the hypothesis that gettering kinetics is governed by not only the total iron concentration but also by the distribution of precipitated iron. Finally, future directions based on the modeling are suggested for the improvement of effective minority carrier lifetime in multicrystalline silicon solar cells.
International
Si
JCR
Si
Title
Journal of Applied Physics
ISBN
0021-8979
Impact factor JCR
2,21
Impact info
Volume
113
Journal number
From page
044521-1
To page
044521-12
Month
SIN MES
Ranking
Participants
  • Autor: D.P. Fenning
  • Autor: J. Hofstetter
  • Autor: M.I. Bertoni
  • Autor: G. Coletti
  • Autor: B. Lai
  • Autor: Carlos del Cañizo Nadal UPM
  • Autor: T. Buonassisi
Research Group, Departaments and Institutes related
  • Creador: Grupo de Investigación: Silicio y Nuevos Conceptos para Células Solares
  • Centro o Instituto I+D+i: Instituto de Energía Solar
  • Departamento: Electrónica Física