M. Weizman

Controlling the thermal impact of ns laser pulses for the preparation of the P2 interconnect by local phase transformation in CIGSe

The thermal impact of nanosecond laser pulses was beneficially employed and well-controlled for the preparation of the P2 interconnect by local phase transformation (i.e., by drawing conductive lines rather than removing the material) in CIGSe mini-modules, which were demonstrated to outperform their conventionally needle-patterned counterparts. Conductivity and elemental composition of the scribed lines as well as the extent of the heat-affected area were analyzed, quantified and taken into account for achieving optimal CIGSe solar module performances. This approach opens new prospects for significant simplification of the serial interconnection, since the P2 und the P3 can be scribed simultaneously after deposition of both the CIGSe and the TCO layer.

Electrical and structural functionality of CIGSe solar cells patterned with picosecond laser pulses of different wavelengths

Electrical and structural functionality of monolithic interconnection of CIGSe solar cells by P1-P3 picosecond laser ablation has been successfully established and evaluated as being competitive to conventional needle scribing. In all three patterning steps the material is selectively and completely removed yielding structurally well-defined trenches at high scribing speeds up to 1 m/s. P1 and P2 ps laser scribing clearly improves the solar cell efficiencies whereas P3 scribing is still challenging due to shunts resulting from laser-induced alteration of the absorber material.