Flexible solar cells are where solar power technology is heading in the future. But researchers must find the best material to protect the active layer of the solar cells from the environment. At present, glass is used as the protective layer.
Dr. Klaus Noller of the Fraunhofer Institute for Process Engineering and Packaging bets on thin plastic films. He stated that films are lighter and more flexible than glass. At the institute, Dr. Klaus and his team are creating a new production process that would make it possible to decrease the cost of photovoltaic solar panels.
Instead of using glass panels, the team will print solar cells onto plastic film, which will result into photovoltaic panels that can be rolled. There are two goals that the researchers want to accomplish. These are the film itself and the packaging of the product.
Dr. Klaus Noller is working with Dr. Sabine Amberg-Schwab from the Fraunhofer Institute for Silicate Research ISC. Dr. Amberg-Schwab is an expert in hybrid polymers, called Ormocer. She and her team worked for more than 20 years to develop a coating material based on the hybrid polymer that can be used as a protection layer against water vapor and oxygen.
They created a new type of barrier lacquer that they combined with silicon dioxide, which is a known barrier material. According to Dr. Amberg-Schwab, they observed that adding the two layers had a better barrier effect than they hoped it would be. This is due to the special reactions generated by the two materials.
Then the team developed a method that would make coating the material easy to process and cure. During the damp heat test, the cured lacquer coating was stable at 85 degrees Celsius and 85 percent humidity. The solar cells that would be installed on the roof of a house should be able to withstand different weather conditions and temperatures.
Then another team is developing a process that would apply the barrier layers to the film with the least costs as possible. They called it a roll-to-roll process. A painting line was maximized in real time so that the Ormocer is applied in a dust-free environment. The thickness of the layers must be as thin as possible and continuous in nature. The coated side must not touch one of the rollers at any time because a gentle touch could destroy the layer.
This patented process would make it possible to manufacture low-cost high barrier films in an environmental friendly manner.