By Stephan Buecheler, Laboratory for Thin Films and Photovoltaics, Empa; Fabian Pianezzi, Laboratory for Thin Films and Photovoltaics, Empa; Patrick Reinhard, Laboratory for Thin Films and Photovoltaics, Empa; Enrico Avancini, Laboratory for Thin Films and Photovoltaics, Empa; Lukas Kranz, Researcher, Laboratory for Thin Films and Photovoltaics, Empa; Fan Fu, Laboratory for Thin Films and Photovoltaics, Empa; Ayodhya N. Tiwari, Head of Laboratory for Thin Films and Photovoltaics, Empa
During the past two years remarkable performance improvements have been reported for polycrystalline Cu(In,Ga)Se2 (CIGS), CdTe and perovskite thin-film solar cells. In this paper the key breakthroughs in CIGS thin-film technology are reviewed and the scope for further performance improvements by analysing the stillremaining electrical and optical losses in record-efficiency CIGS solar cells is discussed. On the basis of this analysis it is believed that conversion efficiencies up to 25% are achievable with CIGS solar cells in the mid term. Furthermore, the potential for the concept of polycrystalline multi-junction solar cells to push efficiencies even further, towards 30%, is discussed. Finally, a short review of the CIGS market and an outlook from an industrial perspective are presented.
