Degradation stability of solar cells after laser enhanced contact optimization (LECO)

In this work the influence of the LECO treatment on the typical PERC degradation mechanisms was investigated. It was found that the treatment has no significant impact on the Boron-Oxygen related Light Induced Degradation and Light and elevated Temperature Induced Degradation behavior. Furthermore, it is shown that stabilized cells remain stable after the LECO treatment. Also, we did not find any indication of LECO influencing the Potential Induced Degradation susceptibility. Finally, the variation of the process order of the LECO treatment and the B-O Stabilization Process was analysed and showed no restrictions or differences in the outcome of the solar cell quality or stability. Based on these results it is proposed to implement LECO as an approach to decrease the LeTID-sensitivity by combining LECO with modified firing processes. We claim that a combination of reduced peak firing temperatures with the LECO process leads to a decrease in LeTID sensitivity without any drawbacks in the cells' efficiencies.