Record european efficiency amorphous silicon heterojunction solar cells: final results from the HETSI project

In this work, we present some of the main results obtained within the project “Heterojunction Solar Cells based on a-Si/c-Si” (HETSI) [1], funded by the European Commission in the framework of the 7th Research Framework Program from 2008 to 2011. This project, based on the promising silicon heterojunction technology, represents a concerted effort of the consortium, a well balanced mix of universities, institutes of technology and industrial partners, to combine device modelling, material optimization and characterization, process development (from texturization to metallization), PV cell and module process integration, while cost and environmental issues are addressed as well. Thanks to a better understanding of the device physics from advanced characterization tools and modeling, the results obtained by this consortium have put Europe on the map, with a record cell efficiency of 20,7% on large area n-type c-Si wafers. Moreover, a dedicated module process has been developed with low losses of only 1% absolute from cell to module.