Key developments in CIGS thin film solar cells on ceramic substrates

Nowadays the improvement of the photovoltaic building-integration (BIPV) has become very important. In fact, more emphasis has been put on the possibility of producing photovoltaic modules able to be integrated, or even to be directly assembled to form the so-called ventilated walls for buildings. This integration can be improved by using, alternatively to glass, other materials for the substrate or for the final “box”, in which the solar cells are encapsulated. A good candidate as a substrate material that substitutes the glass is ceramic. This kind of non-transparent substrates is useful in the substrate configuration solar cell technology. An example of this technology is represented by the Cu(In,Ga)Se2-based solar cells. The challenge in this field corresponds to directly use, as a substrate large dimension ceramic tiles, which are commercially available on the market. For this reason, the process technology developed at ThiFiLab for glass substrates has been transferred on this kind of new substrates and some solar cells have been produced showing efficiencies in the range of 12–14%.