I found it googling – this PDF from Nanosolar’s website explaining actually the progress the firm is making developping hte CIGS technology. It’s called ” High-performance Thin-film photovoltaics using Low-cost process technology “. The paper explaining that the CIGS can can deliver sunlight-to-electricity conversion efficiencies of 19.5%. The paper then explains the different fabrication process of CIGS. The roll-printing technology which has been developped by Nanosolar combines high-speed, non-vacuum, wet coating of nanoparticles onto low cost per unit area of metal foil substrates with rapid theremal procesing. (It works actually like Jet Inc printer that you and me using at home, but at bigger scale). This technology is reducing the costs $/m with superior efficiency.