Fraunhofer Institutes and their partners have been looking to increase the market for the textile industry and this led them to the development of textile-based solar cells that they wish to produce in a commercialized scale in the future.
According to Dr. Lars Rebenklau, group manager for system integration and electronic packaging at the Fraunhofer Institute for Ceramic Technologies and Systems or IKTS, there are already a number of methods that allow for incorporation of solar cells in coatings applied to textiles. But, Dr. Jonas Sundqvist, group manager for thin-film technology at the Fraunhofer IKTS, says that even though that sounds easy to do, there are several factors to consider as they state in a report.
One, is that the machines currently used in the textile industry are designed for large rolls of fabric that are about five to six meters wide and up to 100 meters long. Another factor to consider is that during the coating process, the materials must be able to withstand a high temperature of about 200 degrees Celsius.
In terms of reliability of the material, it must be able to meet fire regulations and have a high tensile strength. And in terms of cost, it must be cheap to produce before they can say that the product can be mass-produced. The number of demands of the aspired product has brought together Fraunhofer and its partners together to work on the PhotoTex project.
Another challenge is how flexible textiles are compared to ordinary electronic devices. In order to apply a wafer-thin bottom electrode, the photovoltaic layer, and the top electrode onto the fabric, the researchers used the method of transfer printing to apply an even layer on the surface of the fabric. A standard production technique called the roll-to-roll method was also used to incorporate the two electrodes made of electrically conductive polyester into the fabric. And the solar cells were laminated to further add protection and robustness.
As of now, the product has an efficiency range of 0.1 to 0.3 percent and although the efficiency is currently low, Rebenklau says that what they have produced right now is already able to demonstrate the basic functionality of the textile-based solar cells. The next step to their research is to focus on increasing this efficiency to over five percent.