Page 247 - Mirjam-Theelen-Degradation-of-CIGS-solar-cells

The impact of atmospheric species

Lock in thermography was used to define shunt paths in the solar cells (Figure 8.4).
For the H O/N samples, shunt paths were observed along the edges of the solar cell,
2
2
while the other samples did not reveal any shunt paths.
Cross-section SEM was used to determine the structural changes (Figure 8.5). These
measurements showed that the morphology of the molybdenum and the bottom
part of the CIGS layer remained the same, while large structural changes were found

(a) (b)

H 2 O/air
H 2 O/N 2
Figure 8.4
Lock in thermography pictures of the surface of the (a) H 2 O/N 2 and (b) H 2 O/air samples after 340 hours exposure. The white/
green/red dots indicate the position of shunt paths.

Figure 8.5 Figure 5: Cross-section SEM pictures of CIGS solar cells (right) and zooms to
the CIGS/CdS/i-ZnO/ZnO:Al region (left) after exposure to various conditions.
Cross-section SEM pictures of CIGS solar cells (right) and zooms to the CIGS/CdS/i-ZnO/ZnO:Al region (left) after exposure to
various conditions.

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