Analysis of copper penetration in selective-emitter silicon solar cells using laser ablation inductively-coupled plasma mass spectrometry

This paper reports on an investigation into the use of laser ablation inductively-coupled plasma mass spectrometry (LA-ICPMS) in analyzing copper diffusion through nickel barrier layers in selective-emitter silicon solar cells. Cells plated with nickel and copper were heat-treated at 200 °C for up to 15 hours. Following quenching in ethylene glycol, significant degradation was observed in the plated cells, whereas no degradation was observed in the slow cooled cells. Impurity analysis with high spatial resolution was obtained with LA-ICPMS, showing higher copper content in copper-plated cells after heat treatment compared to cells without copper plating or heat treatment. The limitations of LA-ICPMS for quantitative analysis and the importance of minimizing surface contamination to improve technique sensitivity are also highlighted.