Optimisation of cell interconnectors for PV module performance enhancement

In commercial crystalline silicon PV modules usually two parallel metallic strings are used to collect the current from the grid and interconnect the individual cells. Typically, the cross section of these cell interconnectors is rectangular, they are approx. 100 µm high and about 2-3 mm wide, resulting in a 4-6% shadow loss. The basic idea of this paper is to use structured cell interconnectors to increase the short circuit current by taking advantage from multiple internal reflections inside the module compound. A structure on top of the interconnectors has to be designed in a way that light being incident on the interconnectors is reflected under an angel suitable for total internal reflection at the glass/air boundary. A new structuring type called TRITOP has been experimentally and theoretically investigated to check whether a significant enhancement of PV module performance is achievable. An increase of 2-3% relative in module efficiency seems to be cost-effectively transferable to PV module production soon.