CLC number: TB12; TB30
On-line Access: 2017-01-03
Received: 2015-10-21
Revision Accepted: 2016-04-07
Crosschecked: 2016-12-12
Cited: 0
Clicked: 4595
Chih-Hung Chen, Hsuan-Teh Hu, Fu-Ming Lin, Hsin-Hsin Hsieh. Residual stress analysis and bow simulation of crystalline silicon solar cells[J]. Journal of Zhejiang University Science A, 2017, 18(1): 49-58.
@article{title="Residual stress analysis and bow simulation of crystalline silicon solar cells",
author="Chih-Hung Chen, Hsuan-Teh Hu, Fu-Ming Lin, Hsin-Hsin Hsieh",
journal="Journal of Zhejiang University Science A",
volume="18",
number="1",
pages="49-58",
year="2017",
publisher="Zhejiang University Press & Springer",
doi="10.1631/jzus.A1500279"
}
%0 Journal Article
%T Residual stress analysis and bow simulation of crystalline silicon solar cells
%A Chih-Hung Chen
%A Hsuan-Teh Hu
%A Fu-Ming Lin
%A Hsin-Hsin Hsieh
%J Journal of Zhejiang University SCIENCE A
%V 18
%N 1
%P 49-58
%@ 1673-565X
%D 2017
%I Zhejiang University Press & Springer
%DOI 10.1631/jzus.A1500279
TY - JOUR
T1 - Residual stress analysis and bow simulation of crystalline silicon solar cells
A1 - Chih-Hung Chen
A1 - Hsuan-Teh Hu
A1 - Fu-Ming Lin
A1 - Hsin-Hsin Hsieh
J0 - Journal of Zhejiang University Science A
VL - 18
IS - 1
SP - 49
EP - 58
%@ 1673-565X
Y1 - 2017
PB - Zhejiang University Press & Springer
ER -
DOI - 10.1631/jzus.A1500279
Abstract: The pressure to reduce solar energy costs encourages efforts to reduce the thickness of silicon wafers. Thus, the cell bowing problem associated with the use of thin wafers has become increasingly important, as it can lead to the cracking of cells and thus to high yield losses. In this paper, a systematic approach for simulating the cell bowing induced by the firing process is presented. This approach consists of three processes: (1) the material properties are determined using a nanoidentation test; (2) the thicknesses of aluminum (Al) paste and silver (Ag) busbars and fingers are measured using scanning electron microscopy; (3) non-linear finite element analysis (FEA) is used for simulating the cell bowing induced by the firing process. As a result, the bowing obtained using FEA simulation agrees better with the experimental data than that using the bowing calculations suggested in literature. In addition, the total in-plane residual stress state in the wafer/cell due to the firing process can be determined using the FEA simulation. A detailed analysis of the firing-induced stress state in single crystalline silicon (sc-Si), cast, and edge-defined film-fed growth (EFG) multi-crystalline silicon wafers of different thicknesses is presented. Based on this analysis, a simple residual stress calculation is developed to estimate the maximum in-plane principal stress in the wafers. It is also proposed that the metallization pattern, Ag busbars and fingers screen printed on the front of a solar cell, can be designed using this approach. A practical case of a 3-busbar Si solar cell is presented.
The paper demonstrates a systematic approach to evaluate the mechanical properties of wafers and solar cells. The FEA simulation proposed by the authors provides accurate bowing results and the stress distribution for various types of Si wafer, that agree well with experiments. The research results are quite interesting, which can be used to estimate the possibility of breakage in solar cell fabrication.
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