Journal of Materials Science

, Volume 45, Issue 6, pp 1560–1566 | Cite as

Mechanical properties of polycrystalline silicon solar cell feed stock grown via fluidized bed reactors

  • M. B. Zbib
  • M. C. Tarun
  • M. G. Norton
  • D. F. Bahr
  • R. Nair
  • N. X. Randall
  • E. W. Osborne


Polysilicon granular beads grown via a fluidized bed reactor, a feedstock for silicon solar cell production, were annealed, sectioned, and indented using a combination of nanoindentation and microhardness testing to determine the mechanical response of this commercially available raw material. The granular material, with macroscopic dimensions on the order of millimeters and an internal grain size on the order of 20 nm, has an indentation modulus of approximately 160 GPa, and a hardness prior to fracture of 9.6 GPa; these values are relatively insensitive to annealing at temperatures between 600 and 1100 °C. Indentation fracture testing suggests the toughness of this material is on the order of 0.6 MPa m1/2. The fracture sequence has been verified using acoustic emission testing during indentation. Annealing in air at 600 °C for 3 days increases the toughness by approximately 50% with little change in grain size. The as grown material contains solute hydrogen, identified by infrared spectroscopy, from the growth process; annealing in air tends to remove solute hydrogen from the material at temperatures above 1050 °C. The removal of solute hydrogen appears to cause slight increases in toughness, while grain growth at elevated annealing temperatures or the formation of hydrogen complexes in the silicon appears to decrease toughness. The results suggest thermal treatments of silicon grown with this method can moderately alter the friability of the final product.


Fracture Toughness Acoustic Emission Polysilicon Single Crystal Silicon Silicon Solar Cell 



We would like to thank M.M. Dahl for help in sample preparation, microscopy for Fig. 1, and technique development in the handling of silicon granules grown by the FBR.


  1. 1.
    Caussat B, Hemati M, Couderc JP (1995) Chem Eng Sci 50:3615CrossRefGoogle Scholar
  2. 2.
    Dahl MM, Bellou A, Bahr DF, Norton MG, Osborne EW (2009) J Cryst Growth 311:1496CrossRefADSGoogle Scholar
  3. 3.
    Ballarini R, Mullen RL, Yin Y, Kahn H, Stemmer S, Heuer AH (1997) J Mater Res 12:915CrossRefADSGoogle Scholar
  4. 4.
    Cook RF (2006) J Mater Sci 41:841. doi: 10.1007/s10853-006-6567-y CrossRefADSGoogle Scholar
  5. 5.
    Chiao YH, Clarke DR (1989) Acta Met 37:203CrossRefGoogle Scholar
  6. 6.
    John CFSt (1975) Philos Mag 32:1193CrossRefADSGoogle Scholar
  7. 7.
    Brede M, Hansen P (1988) Acta Met 36:2003CrossRefGoogle Scholar
  8. 8.
    Hirsch PB, Samuels J, Roberts SG (1989) Proc R Soc Lond A 421:25CrossRefADSGoogle Scholar
  9. 9.
    Chen CP, Leipold MH (1980) Am Ceram Soc Bull 59:469Google Scholar
  10. 10.
    George A, Michot G (1993) Mater Sci Eng A 164:118CrossRefGoogle Scholar
  11. 11.
    Ericson F, Johansson S, Schweitz JA (1988) Mat Sci Eng A 105:131CrossRefGoogle Scholar
  12. 12.
    Ebrahimi F, Kalwani L (1999) Mat Sci Eng A 268:116CrossRefGoogle Scholar
  13. 13.
    Fancher RW, Watkins CM, Norton MG, Bahr DF, Osborne EW (2001) J Mater Sci 36:5441. doi: 10.1023/A:1012425529753 CrossRefGoogle Scholar
  14. 14.
    Brodie RC, Bahr DF (2003) Mat Sci Eng A 351:166CrossRefGoogle Scholar
  15. 15.
    Sharpe WN, Yuan B, Edwards RL (1997) Mat Res Soc Symp Proc 505:51Google Scholar
  16. 16.
    Tsuchiya T, Sakata J, Taga Y (1997) Mat Res Soc Symp Proc 505:285Google Scholar
  17. 17.
    Kahn H, Tayebi N, Ballarini R, Mullen RL, Heuer AH (2000) Sens Actuators A 82:274CrossRefGoogle Scholar
  18. 18.
    Oliver WC, Pharr GM (1992) J Mater Res 7:1564CrossRefADSGoogle Scholar
  19. 19.
    Morris DJ, Cook RF (2005) Int J Fract 136:237CrossRefGoogle Scholar
  20. 20.
    Morris DJ, Vodnick AM, Cook RF (2005) Int J Fract 136:265CrossRefGoogle Scholar
  21. 21.
    Cook RF, Pharr GM (1990) J Am Ceram Soc 73:787CrossRefGoogle Scholar
  22. 22.
    von Keudell A, Abelson JR (1998) J Appl Phys 84:489CrossRefADSGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  • M. B. Zbib
    • 1
  • M. C. Tarun
    • 1
  • M. G. Norton
    • 1
  • D. F. Bahr
    • 1
  • R. Nair
    • 2
  • N. X. Randall
    • 2
  • E. W. Osborne
    • 3
  1. 1.Mechanical and Materials EngineeringWashington State UniversityPullmanUSA
  2. 2.CSM Instruments Inc.NeedhamUSA
  3. 3.REC SiliconMoses LakeUSA

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