The researchers at the Fraunhofer Institute have come up with a new method of protecting photovoltaic cells by using plastic film. Dr. Klaus Noller, explained that glass plates are usually used for protecting photovoltaic cells, based on the idea Fraunhofer scientists propose to encapsulate photovoltaic cells in a plastic barrier film. He added that the plastic films are much lighter and more flexible when compared to glass plates.
Dr. Sabine Amberg-Schwab and Dr. Klaus Noller have developed a specially coated polymer film that is ideally suited for encapsulating inorganic solar cells.
The research team is led by Dr.KlausNoller, from the film packaging division, and Dr.Sabine Amberg-Schwab, from the Sillicate Research division and an expert in hybrid polymers called ORMOCER. She has worked on the development of ORMOCER for almost 20 years and has come up with an effective barrier film coating by combining silicon dioxide along with the hybrid polymer. In order to use the hybrid polymer as a protective coating for photovoltaic cells, the research team has modified its properties by making it easy to process and cure. The damp heat testing process was the most challenging one, where the cured lacquer coating was required to exhibit stability when subjected to a temperature of 85° Celsius and humidity of 85%. The photovoltaic cells that are placed on roof tops are expected to withstand rough weather conditions over long periods of time.
The task of developing a process for fitting the protective layers perfectly over the film was the real test for the researchers at the Freisinger Institute. They accomplished this by implementing the roll-to-roll process. An important criteria for the application of the hybrid polymer coating is that a dust free environment must be maintained and the thickness of the layer must be very thin and be deposited as a continuous film . During the process, it should be kept in mind that the coated side must never come in contact with any of the rollers. This method of manufacture is a cost-effective and an environment friendly process.
Source: http://www.fraunhofer.de/