Stang, J.-C.; Franssen, T.; Haschke, J.; Mews, M.; Merkle, A.; Peibst, R.; Rech, B.; Korte, L.: Optimised Metallisation for Interdigitated Back Contact Silicon Heterojunction Solar Cells. Solar RRL 1 (2017), p. 1700021/1-11
10.1002/solr.201700021
Abstract:
We report on the design and manufacturing of interdigitat-ed back contact cells based on the silicon heterojunction technology. The influence of geometry and overlap of the doped amorphous silicon layers forming the contact fin-gers on device performance have been investigated by simulation. Two contact formation concepts, with and without a TCO interlayer – an indium tin oxide/silver (ITO/Ag) stack, and a direct aluminium (Al) metallisation – are experimentally evaluated. The former retains good passivation but leads to a too high contact resistivity, the latter shows the opposite behaviour, but yields a slight benefit in terms of overall performance achieving more than 20 % of efficiency. We show that in this case a con-tact system is formed whose properties can be tuned by annealing enabling a trade-off between VOC and FF.