ADEM Publications, Presentations and other output

ADEM--14-044

Title:

Characterization of Multicrystalline Silicon Solar Wafers Fracture Strength and Influencing Factors

Author(s)

Popovich, Vera;

Identification

ISBN

DOI

Publication date

2013-03-01

Number of pages

9

Full text

PDF

Abstract

Silicon wafer thickness reduction without increasing the wa-fer strength leads to a high fracture rate during subsequent handling and processing steps. Cracking of solar cells has also become one of the major sources of solar module failure and rejection. Hence, it is important to evaluate the mechani-cal strength of silicon solar wafers and factors influencing this. The purpose of this work is to understand the fracture behaviour of multicrystalline silicon wafers and to provide information regarding the bending strength of the wafers. The effects on silicon wafer strength of saw damage and of, grain size, grain boundaries and triple junctions are investi-gated. Also the effects of surface roughness and of the dam-age layer removal process are considered. Significant chang-es in fracture strength are found as a result of different sili-con wafer crystallinity and surface roughness. It was found that fracture strength of the processed silicon wafer is mainly affected by the following factors: the thickness of the saw-damage layer (cracks length), surface roughness, cracks/defects at the edges and the amount of grain bounda-ries, serving as potential crack initiation points.