THIN-FILM BARRIERS FOR DURABLE THIN-FILM PV MODULES

This contribution describes thin-film barrier coatings to enhance the stability of silicon thin-film solar modules. Thin-film barriers are applied to protect the modules from degradation in humid environment. Demonstrator modules were exposed to indoor and outdoor tests to evaluate failure modes by electrochemical corrosion during operation. Test results reveal some major failure modes, but we demonstrate long lifetimes under operational conditions for certain modules without conventional encapsulation. These modules without conventional encapsulation showed less than 1% relative degradation during 1000 hours of damp-heat tests with light exposure at open circuit voltage. These promising results will guide the way to new encapsulation concepts for longer lifetimes and/or new low-cost concepts. This approach might be applied to any thin-film technology and will be an important aspect for consumer electronics with less strict requirements for very long-term operation.