Advanced Solar Cell Metallization

We propose a resilient silver flake based metallization technology directly printable onto multijunction solar cells. The metallization will be loaded with carbon nanotubes to improve crack resilience. We will demonstrate that we can maintain connectivity (< 5% performance degradation) of a printed front-side metal layer across a gap up to 30 microns. In Phase I, we demonstrated metal line resistivity that is comparable with the current state of the art. We demonstrated metallization reliability through thermal cycling from -196C to +150C for 20 cycles. More extensive compliance testing and characterization will be completed in Phase II. We use only space-qualified materials in the Phase I and Phase II programs. The proposed printing approach is suitable for low-cost, high-volume deposition. Phase II will also focus on narrowing the front side metallization line width to 15 microns and performing characterization needed to demonstrate space qualification and mission lifetime. The metallization will be integrated with the triple junction solar cell fabrication process. Applied Nanotech Inc. has extensive experience in developing metal-based inks and pastes for solar applications as well as experience with carbon nanotube composite materials for many applications.