This work was supported by the Silicon Solar Consortium (SiSoC) as part of NSF's Industry/University Cooperative Research Center (I/UCRC) program.
Fracture Strength of Photovoltaic Silicon Wafers Evaluated Using a Controlled Flaw Method†
Article first published online: 25 APR 2013
Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Advanced Engineering Materials
Volume 15, Issue 8, pages 756–760, August 2013
How to Cite
Shi, M., Youssef, K. and Rozgonyi, G. A. (2013), Fracture Strength of Photovoltaic Silicon Wafers Evaluated Using a Controlled Flaw Method. Adv. Eng. Mater., 15: 756–760. doi: 10.1002/adem.201200312
- Issue published online: 2 AUG 2013
- Article first published online: 25 APR 2013
- Manuscript Accepted: 27 FEB 2013
- Manuscript Received: 11 OCT 2012
Propagation of pre-existing micro cracks and their associated residual contact stresses, generated from the wafer sawing process, is the leading cause for photovoltaic (PV) silicon wafer/cell breakage during handling and processing. In the current work, the impact of a single micro crack on the fracture strength of PV silicon wafer is investigated based on a controlled flaw method. Radial/median cracks with controllable scales are introduced through microindentation at the center of a PV silicon sample to simulate micro cracks resulting from wafer sawing, handling, or thermal processing. Results indicate that the fracture strength of PV silicon wafer decreases linearly with the increasing of the microindentation load (radial crack scale). In addition, it is found that the impurity carbon plays an important role in the contact cracking-fracture process. The fracture strength increased ≈21% when the substitutional carbon concentration is increased from 1.2 × 1018 to 6.4 × 1018 cm−3.