Dislocation density reduction limited by inclusions in kerfless high‐performance multicrystalline silicon |
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| Authors: | Sergio Castellanos Tonio Buonassisi |
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| Affiliation: | Massachusetts Institute of Technology, Cambridge, USA |
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| Abstract: | Kerfless high‐performance multicrystalline silicon is an emerging material for photovoltaic applications that is characterized by having a smaller grains, and general lower average dislocation density than conventional ribbon multicrystalline silicon. Although a significant improvement over state‐of‐the‐art, dislocation reduction at the crystal growth stage is not complete. Here we employ an annealing process previously tested in conventional ingot mc‐Si to reduce dislo‐ cation clusters that remain after crystal growth. A sample is subjected to a 1390 °C annealing process for 24 h and its dislocation density reduction is evaluated. We employ infrared birefringence imaging to observe that despite achieving significant average dislocation density reduction, if inclusions are present in the sample, these may serve to nucleate new dislocations due to thermal strain. (© 2015 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim) |
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| Keywords: | multicrystalline silicon annealing dislocation density reduction inclusions infrared birefringence |
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