Patterning ZnO layers with frequency doubled and quadrupled Nd:YAG laser for PV application

We report the feasibility of nanosecond laser patterning of ZnO layer in CIGS-based solar cells. Patterning the ZnO layer on top of the entire solar cell structure (i.e. substrate configuration), as well as scribing the transparent conducting oxide layer on glass substrate (i.e. superstrate configuration) was studied at frequency doubled and quadrupled Nd:YAG wavelengths. We found that the 100 nm ZnO/glass structure can easily be patterned by both wavelengths, while for the 1 μm thick layer better results were achieved with UV pulses. In the substrate configuration patterning with the visible laser permits controllable cutting, while even mild UV processing causes severe damage to the underlying CIGS layer.