Development of Insulated Steel Substrate for PV Applications Using Roll-to-Roll Deposition Lines

Reducing the costs for producing photovoltaic modules is mandatory to make solar energy more attractive and competitive compared to fossil energy. Flexible substrates have gained an increasing interest because they offer a large panel of applications as well as the possibility of industrialization in roll-to-roll process, which could dramatically reduce the costs of production. Among the flexible and lightweight substrates, flat carbon steel is an excellent candidate, because it is cheap and can withstand very high temperature. Herein we demonstrate the deposition by wet coating of a dielectric layer on flat carbon steel, followed by the deposition by sputtering of the back electrode in roll-to-roll process at a pilot scale. The pilot line is equipped with a disturbance recording function that allows a very good control of the whole process. Functional CIGS-based solar cells have been obtained using this advanced steel substrate. Those developments are conducted within the LIFE-PHOSTER project, which aims at developing new solar technologies and products with low environmental impact.