The transfer of the lab-scale processes into an industrial environment encounters challenges. Several aspects need to be controlled to ensure manufacturing of modules with acceptable efficiency and production yield. Not only material and process-related issues need to be solved but also engineering of new equipment machines and development of in situ process control techniques are required.
Industrial production of CIGS solar modules on glass substrates has advanced to high volumes by companies such as Solar Frontier, AVANCIS, Solibro, Manz, and others. However, the manufacturing of flexible CIGS solar cells and modules is relatively less mature despite decent cell efficiencies have been achieved on small area devices in laboratories.
Flexible substrates allow the use of roll-to-roll deposition techniques, as used in the packaging industry, with the potential advantage of high throughput and compact equipment dimensions for each layer of the solar module stack. For the CIGS absorber deposition by co-evaporation or sputtering, evaporation sources and targets need to be positioned in such a way as to reproduce the CIGS growth conditions from the static processes developed on laboratory scale.
Adequate in situ process control techniques are necessary to ensure stable absorber quality during the continuous deposition onto the moving substrate. As there is a lack of reliable providers for CIGS roll-to-roll deposition equipment, companies such as Flisom have developed custom solutions.