Next generation interconnective laser patterning of CIGS thin film modules

Laser patterning of thin film solar cells has proven technically feasible for all layers but still remains a challenging topic for research and development. We present a method where P2 laser patterning of CIGS thin film solar modules is performed after deposition of the ZnO:Al layer, as opposed to the current state-of-the-art where patterning is performed before the ZnO:Al layer is deposited. This method takes full advantage of the potential of laser processing and works by creating an interconnecting scribe line that “welds” the ZnO:Al and CIGS layers into an electrical contact. In this work we present experimental results of this process on five different sets of CIGS with slightly varying thickness and Cu content. While optimization of the process with respect to the various layers has not been performed, the initial results for CIGS thin film modules show working experimental modules in each set. The best experimental module has a fill factor of 71% and its performance is within the standard deviation of mechanically patterned references. An experimental submodule of 30×30 cm2 size with 10% efficiency was manufactured.