Non-vacuum processed next generation thin film photovoltaics: Towards marketable efficiency and production of CZTS based solar cells

Next generation thin film photovoltaics actually face several great challenges: they have to compete with wafer-based silicon based modules in terms of efficiency, costs and production volume. In order to succeed at the market in the long term, they may need to achieve conversion efficiencies of beyond 15%, and contain solely abundant and non-toxic materials within reliable and ideally flexible modules. CZTS based solar cell technology is currently maybe the most promising approach in order to meet these requirements in the near future. Solution processed CZTSSe laboratory-scale solar cells currently exhibit the highest conversion efficiencies of above 11% for this technology. Nevertheless, the material is still in an R&D stage, implying open questions regarding crystal structure, defects, composition and superior device structure. Several recent publications on CZTS give excellent reviews from basic material questions to device processing subjects. The scope of the present work is to interrelate these issues with the actual and projected medium and long-term manufacturing development and market situation. This shall elaborate relations between market demand and constraints, technology and manufacturing challenges and potentials, as well as (raw) material costs and utilization. Finally, the question is being addressed whether solution processed technologies - in particular CZTS - offer the potential to fabricate next generation thin film devices that are marketable in terms of conversion efficiency as well as sustainable, cost-effective, high-throughput production. (C) 2013 Elsevier Ltd. All rights reserved.