Electrodeposition of Metal Matrix Composites and Materials Characterization for Thin-Film Solar Cells

We have demonstrated that metal matrix composites, which consist of silver-multi-walled carbon nanotube-silver, layer-by-layer stack, can electrically bridge the cracks 40 m that appear in the semiconductor substrates and the composite grid lines. This gap bridging was proven to be repeatable through strained-to-failureclosed-gap repeat cycles. For device demonstration, the composites were integrated onto commercial triple-junction cells, and the composite-enhanced cells showed strong crack-tolerance, maintaining 95 of the short circuit current upon substrate fracture. By contrast, the conventional metallization led to 50loss in short circuit current. The composite metallization was also superior in minimizing the overall efficiency loss against fracture, compared to the conventional metallization. During the project extension period, we have initiated composite materials modeling and circuit modeling to establish microstructure-mechanicalelectrical property relationship.