TY - JOUR
T1 - Quantitative mapping of deflection and stress on encapsulated silicon solar cells
AU - Meng, Xiaodong
AU - Stuckelberger, Michael
AU - Ding, Laura
AU - West, Bradley
AU - Jeffries, April
AU - Bertoni, Mariana
N1 - Funding Information:
Manuscript received June 5, 2017; revised July 27, 2017 and September 22, 2017; accepted October 10, 2017. Date of publication November 28, 2017; date of current version December 20, 2017. This work was supported by the Advanced Research Projects Agency-Energy, U.S. Department of Energy, under Award Number DE-AR0000474. (Corresponding author: Mariana Bertoni.) X. Meng and A. Jeffries are with the School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ 85287-5706 USA (e-mail: xmeng21@asu.edu; amjeffri@asu.edu).
Publisher Copyright:
© 2017 IEEE.
PY - 2018/1
Y1 - 2018/1
N2 - The lamination process of photovoltaic modules relies on the application of high temperatures and pressures, which inherently introduces different amounts of expansion and shrinkage of the individual layers including glass, solar cells, polymeric encapsulants, and backsheet. There is no doubt that these effects translate into the cell in the form of deflection and stresses. Thus far though, only the consequences of this have been tracked in terms of failure modes-microcracks, delamination, stress points, etc. The general approaches have been applied to optimize processes with a focus on encapsulant properties, such as degree of cross-linking, moisture permeability, and their long-term lifetime, overlooking their effect on the solar cells. Module reliability is a major driver to lower the levelized cost of electricity and the bankability of projects, and more effort needs to be placed in predictive failure analysis and the optimization of the module components from the point of view of the active components-the cells. In this paper, we propose an in-house X-ray based technique as a novel approach to assess the state of the solar cell under polymeric encapsulation inside a fully assembled module. This gives access for the first time not only to the evaluation of cracks and microdefects, but also to the cell deflection and stress distribution inside the encapsulation.
AB - The lamination process of photovoltaic modules relies on the application of high temperatures and pressures, which inherently introduces different amounts of expansion and shrinkage of the individual layers including glass, solar cells, polymeric encapsulants, and backsheet. There is no doubt that these effects translate into the cell in the form of deflection and stresses. Thus far though, only the consequences of this have been tracked in terms of failure modes-microcracks, delamination, stress points, etc. The general approaches have been applied to optimize processes with a focus on encapsulant properties, such as degree of cross-linking, moisture permeability, and their long-term lifetime, overlooking their effect on the solar cells. Module reliability is a major driver to lower the levelized cost of electricity and the bankability of projects, and more effort needs to be placed in predictive failure analysis and the optimization of the module components from the point of view of the active components-the cells. In this paper, we propose an in-house X-ray based technique as a novel approach to assess the state of the solar cell under polymeric encapsulation inside a fully assembled module. This gives access for the first time not only to the evaluation of cracks and microdefects, but also to the cell deflection and stress distribution inside the encapsulation.
KW - Deflection
KW - Encapsulation
KW - Module lamination
KW - Reliability
KW - Solar cell
KW - Strain
KW - Stress
KW - X-ray topography (XRT)
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U2 - 10.1109/JPHOTOV.2017.2768959
DO - 10.1109/JPHOTOV.2017.2768959
M3 - Article
AN - SCOPUS:85037618497
SN - 2156-3381
VL - 8
SP - 189
EP - 195
JO - IEEE Journal of Photovoltaics
JF - IEEE Journal of Photovoltaics
IS - 1
ER -