Smart Energy Technologies & Energy Storage
Transparent conductors (TCs) are essential components of thin film PV cells. Inherently, ITO and other related TC oxides, have fundamental trade-offs that balance conductivity versus optical transmission losses from metallic absorption and reflectivity. Furthermore, the ITO sputtering, materials and patterning costs represent one of the highest cost elements in the thin film cell process. As we consider emerging technologies such as roll to roll processing on lower temperature substrates, the problem is compounded by high ITO processing temperatures. Low temperature alternatives do exist, however, they cannot reach the metrics for high efficiency PV on their own. Numerical modeling has shown that combining high transparency, modestly conducting films with printed conductive grids can provide a TC with a 30% reduction in power loss relative to ITO. During this talk, current work on nanowire and printed TC films will be presented and the scale-up pathways for these technologies will be discussed.